*: rebase changes from v4.3.3-coreos #6

crawford · 2016-01-12T05:36:48Z

No description provided.

Provide a single call to allow kernel code to determine whether the system has been configured to either disable module loading entirely or to load only modules signed with a trusted key. Bugzilla: N/A Upstream-status: Fedora mustard. Replaced by securelevels, but that was nak'd Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

Any hardware that can potentially generate DMA has to be locked down from userspace in order to avoid it being possible for an attacker to modify kernel code, allowing them to circumvent disabled module loading or module signing. Default to paranoid - in future we can potentially relax this for sufficiently IOMMU-isolated devices. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

IO port access would permit users to gain access to PCI configuration registers, which in turn (on a lot of hardware) give access to MMIO register space. This would potentially permit root to trigger arbitrary DMA, so lock it down by default. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

custom_method effectively allows arbitrary access to system memory, making it possible for an attacker to circumvent restrictions on module loading. Disable it if any such restrictions have been enabled. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

We have no way of validating what all of the Asus WMI methods do on a given machine, and there's a risk that some will allow hardware state to be manipulated in such a way that arbitrary code can be executed in the kernel, circumventing module loading restrictions. Prevent that if any of these features are enabled. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

Allowing users to write to address space makes it possible for the kernel to be subverted, avoiding module loading restrictions. Prevent this when any restrictions have been imposed on loading modules. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

…cted This option allows userspace to pass the RSDP address to the kernel, which makes it possible for a user to circumvent any restrictions imposed on loading modules. Disable it in that case. Signed-off-by: Josh Boyer <jwboyer@redhat.com>

…ictions kexec permits the loading and execution of arbitrary code in ring 0, which is something that module signing enforcement is meant to prevent. It makes sense to disable kexec in this situation. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

Writing to MSRs should not be allowed if module loading is restricted, since it could lead to execution of arbitrary code in kernel mode. Based on a patch by Kees Cook. Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

…Boot mode UEFI Secure Boot provides a mechanism for ensuring that the firmware will only load signed bootloaders and kernels. Certain use cases may also require that all kernel modules also be signed. Add a configuration option that enforces this automatically when enabled. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

The functionality of the config option is dependent upon the platform being UEFI based. Reflect this in the config deps. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>

UEFI machines can be booted in Secure Boot mode. Add a EFI_SECURE_BOOT bit for use with efi_enabled. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>

There is currently no way to verify the resume image when returning from hibernate. This might compromise the signed modules trust model, so until we can work with signed hibernate images we disable it in a secure modules environment. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>

Provide two new security hooks for use with security files that are used when a file is copied up between layers: (1) security_inode_copy_up(). This is called so that the security label on the destination file can be set appropriately. (2) security_inode_copy_up_xattr(). This is called so that each xattr being copied up can be vetted - including modification and discard. Signed-off-by: David Howells <dhowells@redhat.com>

Use the copy-up security hooks previously provided to allow an LSM to adjust the security on a newly created copy and to filter the xattrs copied to that file copy. Signed-off-by: David Howells <dhowells@redhat.com>

Provide stubs for union/overlay copy-up handling. The xattr copy up stub discards lower SELinux xattrs rather than letting them be copied up so that the security label on the copy doesn't get corrupted. Signed-off-by: David Howells <dhowells@redhat.com>

Handle the opening of a unioned file by trying to derive the label that would be attached to the union-layer inode if it doesn't exist. If the union-layer inode does exist (as it necessarily does in overlayfs, but not in unionmount), we assume that it has the right label and use that. Otherwise we try to get it from the superblock. If the superblock has a globally-applied label, we use that, otherwise we try to transition to an appropriate label. This union label is then stored in the file_security_struct. We then perform an additional check to make sure that the calling task is granted permission by the union-layer inode label to open the file in addition to a check to make sure that the task is granted permission to open the lower file with the lower inode label. Signed-off-by: David Howells <dhowells@redhat.com>

File operations (eg. read, write) issued against a file that is attached to the lower layer of a union file needs to be checked against the union-layer label not the lower layer label. The union label is stored in the file_security_struct rather than being retrieved from one of the inodes. Signed-off-by: David Howells <dhowells@redhat.com>

Rather than always allocating the high-order XATTR_SIZE_MAX buffer which is costly and prone to failure, only allocate what is needed and realloc if necessary. Fixes coreos/bugs#489

This enables relocating source and build trees to different roots, provided they stay reachable relative to one another. Useful for builds done within a sandbox where the eventual root is prefixed by some undesirable path component.

If a user opens a file r/w on overlayfs, and if the underlying inode is currently still on the lower fs, right now we're verifying whether selinux policy permits writes to the selinux context on the underlying inode. This is suboptimal, since we don't want confined processes to be able to write to these files if they're able to escape from a container and so don't want to permit this in policy. Have overlayfs pass down an additional flag when verifying the permission on lower inodes, and mask off the write bits in the selinux permissions check if that flag is set.

crawford · 2016-01-12T05:37:47Z

/cc @mjg59

I had to tweak 1b43518, changing the bit from 9 to 10.

marineam · 2016-01-12T05:38:25Z

Wouldn't this be "rebase" for "forward-port" changes ;-)

crawford · 2016-01-12T05:43:59Z

Indeed.

mjg59 · 2016-01-12T06:56:51Z

@crawford That's fine - the bit isn't user-visible

*: rebase changes from v4.3.3-coreos

commit 89da619 upstream. Kernel panic when with high memory pressure, calltrace looks like, PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java" #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb #1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942 #2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30 #3 [ffff881ec7ed7778] oops_end at ffffffff816902c8 #4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46 #5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc #6 [ffff881ec7ed7838] __node_set at ffffffff81680300 #7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f #8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5 #9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8 [exception RIP: _raw_spin_lock_irqsave+47] RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8 RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008 RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098 R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 It happens in the pagefault and results in double pagefault during compacting pages when memory allocation fails. Analysed the vmcore, the page leads to second pagefault is corrupted with _mapcount=-256, but private=0. It's caused by the race between migration and ballooning, and lock missing in virtballoon_migratepage() of virtio_balloon driver. This patch fix the bug. Fixes: e225042 ("virtio_balloon: introduce migration primitives to balloon pages") Cc: stable@vger.kernel.org Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Huang Chong <huang.chong@zte.com.cn> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a5ba1d9 upstream. We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 #2 [ffff88085c6db830] oops_end at ffffffff81008ae7 #3 [ffff88085c6db860] no_context at ffffffff81050b8f #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d #20 [ffff88085c6dbeb0] kthread at ffffffff81096384 #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <tycho@tycho.ws> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 286e877 upstream. Commit efda1b5 ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling") Introduced additional hardening for ambiguity in the ACPI spec for ars_status output sizing. However, it had a couple of cases mixed up. Where it should have been checking for (and returning) "out_field[1] - 4" it was using "out_field[1] - 8" and vice versa. This caused a four byte discrepancy in the buffer size passed on to the command handler, and in some cases, this caused memory corruption like: ./daxdev-errors.sh: line 76: 24104 Aborted (core dumped) ./daxdev-errors $busdev $region malloc(): memory corruption Program received signal SIGABRT, Aborted. [...] #5 0x00007ffff7865a2e in calloc () from /lib64/libc.so.6 #6 0x00007ffff7bc2970 in ndctl_bus_cmd_new_ars_status (ars_cap=ars_cap@entry=0x6153b0) at ars.c:136 #7 0x0000000000401644 in check_ars_status (check=0x7fffffffdeb0, bus=0x604c20) at daxdev-errors.c:144 #8 test_daxdev_clear_error (region_name=<optimized out>, bus_name=<optimized out>) at daxdev-errors.c:332 Cc: <stable@vger.kernel.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Lukasz Dorau <lukasz.dorau@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Fixes: efda1b5 ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling") Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-of-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a5ba1d9 upstream. We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 #2 [ffff88085c6db830] oops_end at ffffffff81008ae7 #3 [ffff88085c6db860] no_context at ffffffff81050b8f #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d #20 [ffff88085c6dbeb0] kthread at ffffffff81096384 #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <tycho@tycho.ws> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 286e877 upstream. Commit efda1b5 ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling") Introduced additional hardening for ambiguity in the ACPI spec for ars_status output sizing. However, it had a couple of cases mixed up. Where it should have been checking for (and returning) "out_field[1] - 4" it was using "out_field[1] - 8" and vice versa. This caused a four byte discrepancy in the buffer size passed on to the command handler, and in some cases, this caused memory corruption like: ./daxdev-errors.sh: line 76: 24104 Aborted (core dumped) ./daxdev-errors $busdev $region malloc(): memory corruption Program received signal SIGABRT, Aborted. [...] #5 0x00007ffff7865a2e in calloc () from /lib64/libc.so.6 #6 0x00007ffff7bc2970 in ndctl_bus_cmd_new_ars_status (ars_cap=ars_cap@entry=0x6153b0) at ars.c:136 #7 0x0000000000401644 in check_ars_status (check=0x7fffffffdeb0, bus=0x604c20) at daxdev-errors.c:144 #8 test_daxdev_clear_error (region_name=<optimized out>, bus_name=<optimized out>) at daxdev-errors.c:332 Cc: <stable@vger.kernel.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Lukasz Dorau <lukasz.dorau@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Fixes: efda1b5 ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling") Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-of-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes a crash when the report encounters an address that could not be associated with an mmaped region: #0 0x00005555557bdc4a in callchain_srcline (ip=<error reading variable: Cannot access memory at address 0x38>, sym=0x0, map=0x0) at util/machine.c:2329 #1 unwind_entry (entry=entry@entry=0x7fffffff9180, arg=arg@entry=0x7ffff5642498) at util/machine.c:2329 #2 0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50 <unwind_entry>, thread=<optimized out>, ip=18446744073709551615) at util/unwind-libunwind-local.c:586 #3 get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50 <unwind_entry>, arg=0x7ffff5642498, max_stack=<optimized out>) at util/unwind-libunwind-local.c:703 #4 0x0000555555837192 in _unwind__get_entries (cb=<optimized out>, arg=<optimized out>, thread=<optimized out>, data=<optimized out>, max_stack=<optimized out>) at util/unwind-libunwind-local.c:725 #5 0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127, sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498, thread=0x555555c7f6f0) at util/machine.c:2351 #6 thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498, evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8, root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378 #7 0x00005555557ba4ee in sample__resolve_callchain (sample=<optimized out>, cursor=<optimized out>, parent=parent@entry=0x7fffffff97b8, evsel=<optimized out>, al=al@entry=0x7fffffff9750, max_stack=<optimized out>) at util/callchain.c:1085 Signed-off-by: Milian Wolff <milian.wolff@kdab.com> Tested-by: Sandipan Das <sandipan@linux.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Fixes: 2a9d505 ("perf script: Show correct offsets for DWARF-based unwinding") Link: http://lkml.kernel.org/r/20180926135207.30263-1-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

[ Upstream commit f5e2848 ] When enumerating page size definitions to check hardware support, we construct a constant which is (1U << (def->shift - 10)). However, the array of page size definitions is only initalised for various MMU_PAGE_* constants, so it contains a number of 0-initialised elements with def->shift == 0. This means we end up shifting by a very large number, which gives the following UBSan splat: ================================================================================ UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21 shift exponent 4294967286 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6 Call Trace: [c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable) [c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64 [c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4 [c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0 [c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130 [c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80 ================================================================================ Fix this by first checking if the element exists (shift != 0) before constructing the constant. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ebaf39e ] The *_frag_reasm() functions are susceptible to miscalculating the byte count of packet fragments in case the truesize of a head buffer changes. The truesize member may be changed by the call to skb_unclone(), leaving the fragment memory limit counter unbalanced even if all fragments are processed. This miscalculation goes unnoticed as long as the network namespace which holds the counter is not destroyed. Should an attempt be made to destroy a network namespace that holds an unbalanced fragment memory limit counter the cleanup of the namespace never finishes. The thread handling the cleanup gets stuck in inet_frags_exit_net() waiting for the percpu counter to reach zero. The thread is usually in running state with a stacktrace similar to: PID: 1073 TASK: ffff880626711440 CPU: 1 COMMAND: "kworker/u48:4" #5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480 #6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b #7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c #8 [ffff880621563db0] ops_exit_list at ffffffff814f5856 #9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0 #10 [ffff880621563e38] process_one_work at ffffffff81096f14 It is not possible to create new network namespaces, and processes that call unshare() end up being stuck in uninterruptible sleep state waiting to acquire the net_mutex. The bug was observed in the IPv6 netfilter code by Per Sundstrom. I thank him for his analysis of the problem. The parts of this patch that apply to IPv4 and IPv6 fragment reassembly are preemptive measures. Signed-off-by: Jiri Wiesner <jwiesner@suse.com> Reported-by: Per Sundstrom <per.sundstrom@redqube.se> Acked-by: Peter Oskolkov <posk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit c5a94f4 ] It was observed that a process blocked indefintely in __fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP to be cleared via fscache_wait_for_deferred_lookup(). At this time, ->backing_objects was empty, which would normaly prevent __fscache_read_or_alloc_page() from getting to the point of waiting. This implies that ->backing_objects was cleared *after* __fscache_read_or_alloc_page was was entered. When an object is "killed" and then "dropped", FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is ->backing_objects cleared. This leaves a window where something else can set FSCACHE_COOKIE_LOOKING_UP and __fscache_read_or_alloc_page() can start waiting, before ->backing_objects is cleared There is some uncertainty in this analysis, but it seems to be fit the observations. Adding the wake in this patch will be handled correctly by __fscache_read_or_alloc_page(), as it checks if ->backing_objects is empty again, after waiting. Customer which reported the hang, also report that the hang cannot be reproduced with this fix. The backtrace for the blocked process looked like: PID: 29360 TASK: ffff881ff2ac0f80 CPU: 3 COMMAND: "zsh" #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache] #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache] #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs] #7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs] #8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73 #9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs] #10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756 #11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa #12 [ffff881ff43eff18] sys_read at ffffffff811fda62 #13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 6c5c748 ] ibmvnic_reset can create and schedule a reset work item from an IRQ context, so do not use a mutex, which can sleep. Convert the reset work item mutex to a spin lock. Locking debugger generated the trace output below. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908 in_atomic(): 1, irqs_disabled(): 1, pid: 120, name: kworker/8:1 4 locks held by kworker/8:1/120: #0: 0000000017c05720 ((wq_completion)"events"){+.+.}, at: process_one_work+0x188/0x710 #1: 00000000ace90706 ((linkwatch_work).work){+.+.}, at: process_one_work+0x188/0x710 #2: 000000007632871f (rtnl_mutex){+.+.}, at: rtnl_lock+0x30/0x50 #3: 00000000fc36813a (&(&crq->lock)->rlock){..-.}, at: ibmvnic_tasklet+0x88/0x2010 [ibmvnic] irq event stamp: 26293 hardirqs last enabled at (26292): [<c000000000122468>] tasklet_action_common.isra.12+0x78/0x1c0 hardirqs last disabled at (26293): [<c000000000befce8>] _raw_spin_lock_irqsave+0x48/0xf0 softirqs last enabled at (26288): [<c000000000a8ac78>] dev_deactivate_queue.constprop.28+0xc8/0x160 softirqs last disabled at (26289): [<c0000000000306e0>] call_do_softirq+0x14/0x24 CPU: 8 PID: 120 Comm: kworker/8:1 Kdump: loaded Not tainted 4.20.0-rc6 #6 Workqueue: events linkwatch_event Call Trace: [c0000003fffa7a50] [c000000000bc83e4] dump_stack+0xe8/0x164 (unreliable) [c0000003fffa7aa0] [c00000000015ba0c] ___might_sleep+0x2dc/0x320 [c0000003fffa7b20] [c000000000be960c] __mutex_lock+0x8c/0xb40 [c0000003fffa7c30] [d000000006202ac8] ibmvnic_reset+0x78/0x330 [ibmvnic] [c0000003fffa7cc0] [d0000000062097f4] ibmvnic_tasklet+0x1054/0x2010 [ibmvnic] [c0000003fffa7e00] [c0000000001224c8] tasklet_action_common.isra.12+0xd8/0x1c0 [c0000003fffa7e60] [c000000000bf1238] __do_softirq+0x1a8/0x64c [c0000003fffa7f90] [c0000000000306e0] call_do_softirq+0x14/0x24 [c0000003f3f87980] [c00000000001ba50] do_softirq_own_stack+0x60/0xb0 [c0000003f3f879c0] [c0000000001218a8] do_softirq+0xa8/0x100 [c0000003f3f879f0] [c000000000121a74] __local_bh_enable_ip+0x174/0x180 [c0000003f3f87a60] [c000000000bf003c] _raw_spin_unlock_bh+0x5c/0x80 [c0000003f3f87a90] [c000000000a8ac78] dev_deactivate_queue.constprop.28+0xc8/0x160 [c0000003f3f87ad0] [c000000000a8c8b0] dev_deactivate_many+0xd0/0x520 [c0000003f3f87b70] [c000000000a8cd40] dev_deactivate+0x40/0x60 [c0000003f3f87ba0] [c000000000a5e0c4] linkwatch_do_dev+0x74/0xd0 [c0000003f3f87bd0] [c000000000a5e694] __linkwatch_run_queue+0x1a4/0x1f0 [c0000003f3f87c30] [c000000000a5e728] linkwatch_event+0x48/0x60 [c0000003f3f87c50] [c0000000001444e8] process_one_work+0x238/0x710 [c0000003f3f87d20] [c000000000144a48] worker_thread+0x88/0x4e0 [c0000003f3f87db0] [c00000000014e3a8] kthread+0x178/0x1c0 [c0000003f3f87e20] [c00000000000bfd0] ret_from_kernel_thread+0x5c/0x6c Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit ebaf39e ] The *_frag_reasm() functions are susceptible to miscalculating the byte count of packet fragments in case the truesize of a head buffer changes. The truesize member may be changed by the call to skb_unclone(), leaving the fragment memory limit counter unbalanced even if all fragments are processed. This miscalculation goes unnoticed as long as the network namespace which holds the counter is not destroyed. Should an attempt be made to destroy a network namespace that holds an unbalanced fragment memory limit counter the cleanup of the namespace never finishes. The thread handling the cleanup gets stuck in inet_frags_exit_net() waiting for the percpu counter to reach zero. The thread is usually in running state with a stacktrace similar to: PID: 1073 TASK: ffff880626711440 CPU: 1 COMMAND: "kworker/u48:4" #5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480 #6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b #7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c #8 [ffff880621563db0] ops_exit_list at ffffffff814f5856 #9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0 #10 [ffff880621563e38] process_one_work at ffffffff81096f14 It is not possible to create new network namespaces, and processes that call unshare() end up being stuck in uninterruptible sleep state waiting to acquire the net_mutex. The bug was observed in the IPv6 netfilter code by Per Sundstrom. I thank him for his analysis of the problem. The parts of this patch that apply to IPv4 and IPv6 fragment reassembly are preemptive measures. Signed-off-by: Jiri Wiesner <jwiesner@suse.com> Reported-by: Per Sundstrom <per.sundstrom@redqube.se> Acked-by: Peter Oskolkov <posk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit c5a94f4 ] It was observed that a process blocked indefintely in __fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP to be cleared via fscache_wait_for_deferred_lookup(). At this time, ->backing_objects was empty, which would normaly prevent __fscache_read_or_alloc_page() from getting to the point of waiting. This implies that ->backing_objects was cleared *after* __fscache_read_or_alloc_page was was entered. When an object is "killed" and then "dropped", FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is ->backing_objects cleared. This leaves a window where something else can set FSCACHE_COOKIE_LOOKING_UP and __fscache_read_or_alloc_page() can start waiting, before ->backing_objects is cleared There is some uncertainty in this analysis, but it seems to be fit the observations. Adding the wake in this patch will be handled correctly by __fscache_read_or_alloc_page(), as it checks if ->backing_objects is empty again, after waiting. Customer which reported the hang, also report that the hang cannot be reproduced with this fix. The backtrace for the blocked process looked like: PID: 29360 TASK: ffff881ff2ac0f80 CPU: 3 COMMAND: "zsh" #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache] #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache] #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs] #7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs] #8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73 #9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs] #10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756 #11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa #12 [ffff881ff43eff18] sys_read at ffffffff811fda62 #13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit a4b732a upstream. There is a race between cache device register and cache set unregister. For an already registered cache device, register_bcache will call bch_is_open to iterate through all cachesets and check every cache there. The race occurs if cache_set_free executes at the same time and clears the caches right before ca is dereferenced in bch_is_open_cache. To close the race, let's make sure the clean up work is protected by the bch_register_lock as well. This issue can be reproduced as follows, while true; do echo /dev/XXX> /sys/fs/bcache/register ; done& while true; do echo 1> /sys/block/XXX/bcache/set/unregister ; done & and results in the following oops, [ +0.000053] BUG: unable to handle kernel NULL pointer dereference at 0000000000000998 [ +0.000457] #PF error: [normal kernel read fault] [ +0.000464] PGD 800000003ca9d067 P4D 800000003ca9d067 PUD 3ca9c067 PMD 0 [ +0.000388] Oops: 0000 [#1] SMP PTI [ +0.000269] CPU: 1 PID: 3266 Comm: bash Not tainted 5.0.0+ #6 [ +0.000346] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.fc28 04/01/2014 [ +0.000472] RIP: 0010:register_bcache+0x1829/0x1990 [bcache] [ +0.000344] Code: b0 48 83 e8 50 48 81 fa e0 e1 10 c0 0f 84 a9 00 00 00 48 89 c6 48 89 ca 0f b7 ba 54 04 00 00 4c 8b 82 60 0c 00 00 85 ff 74 2f <49> 3b a8 98 09 00 00 74 4e 44 8d 47 ff 31 ff 49 c1 e0 03 eb 0d [ +0.000839] RSP: 0018:ffff92ee804cbd88 EFLAGS: 00010202 [ +0.000328] RAX: ffffffffc010e190 RBX: ffff918b5c6b5000 RCX: ffff918b7d8e0000 [ +0.000399] RDX: ffff918b7d8e0000 RSI: ffffffffc010e190 RDI: 0000000000000001 [ +0.000398] RBP: ffff918b7d318340 R08: 0000000000000000 R09: ffffffffb9bd2d7a [ +0.000385] R10: ffff918b7eb253c0 R11: ffffb95980f51200 R12: ffffffffc010e1a0 [ +0.000411] R13: fffffffffffffff2 R14: 000000000000000b R15: ffff918b7e232620 [ +0.000384] FS: 00007f955bec2740(0000) GS:ffff918b7eb00000(0000) knlGS:0000000000000000 [ +0.000420] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000801] CR2: 0000000000000998 CR3: 000000003cad6000 CR4: 00000000001406e0 [ +0.000837] Call Trace: [ +0.000682] ? _cond_resched+0x10/0x20 [ +0.000691] ? __kmalloc+0x131/0x1b0 [ +0.000710] kernfs_fop_write+0xfa/0x170 [ +0.000733] __vfs_write+0x2e/0x190 [ +0.000688] ? inode_security+0x10/0x30 [ +0.000698] ? selinux_file_permission+0xd2/0x120 [ +0.000752] ? security_file_permission+0x2b/0x100 [ +0.000753] vfs_write+0xa8/0x1a0 [ +0.000676] ksys_write+0x4d/0xb0 [ +0.000699] do_syscall_64+0x3a/0xf0 [ +0.000692] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Liang Chen <liangchen.linux@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

… allocation commit a1ad1cc upstream. After memory allocation failure vc_allocate() doesn't clean up data which has been initialized in visual_init(). In case of fbcon this leads to divide-by-0 in fbcon_init() on next open of the same tty. memory allocation in vc_allocate() may fail here: 1097: vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL); on next open() fbcon_init() skips vc_font.data initialization: 1088: if (!p->fontdata) { division by zero in fbcon_init() happens here: 1149: new_cols /= vc->vc_font.width; Additional check is needed in fbcon_deinit() to prevent usage of uninitialized vc_screenbuf: 1251: if (vc->vc_hi_font_mask && vc->vc_screenbuf) 1252: set_vc_hi_font(vc, false); Crash: #6 [ffffc90001eafa60] divide_error at ffffffff81a00be4 [exception RIP: fbcon_init+463] RIP: ffffffff814b860f RSP: ffffc90001eafb18 RFLAGS: 00010246 ... #7 [ffffc90001eafb60] visual_init at ffffffff8154c36e #8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c #9 [ffffc90001eafbc8] con_install at ffffffff8154f624 ... Signed-off-by: Grzegorz Halat <ghalat@redhat.com> Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7298e3b upstream. Currently the calcuation of end_pfn can round up the pfn number to more than the actual maximum number of pfns, causing an Oops. Fix this by ensuring end_pfn is never more than max_pfn. This can be easily triggered when on systems where the end_pfn gets rounded up to more than max_pfn using the idle-page stress-ng stress test: sudo stress-ng --idle-page 0 BUG: unable to handle kernel paging request at 00000000000020d8 #PF error: [normal kernel read fault] PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 1 PID: 11039 Comm: stress-ng-idle- Not tainted 5.0.0-5-generic #6-Ubuntu Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:page_idle_get_page+0xc8/0x1a0 Code: 0f b1 0a 75 7d 48 8b 03 48 89 c2 48 c1 e8 33 83 e0 07 48 c1 ea 36 48 8d 0c 40 4c 8d 24 88 49 c1 e4 07 4c 03 24 d5 00 89 c3 be <49> 8b 44 24 58 48 8d b8 80 a1 02 00 e8 07 d5 77 00 48 8b 53 08 48 RSP: 0018:ffffafd7c672fde8 EFLAGS: 00010202 RAX: 0000000000000005 RBX: ffffe36341fff700 RCX: 000000000000000f RDX: 0000000000000284 RSI: 0000000000000275 RDI: 0000000001fff700 RBP: ffffafd7c672fe00 R08: ffffa0bc34056410 R09: 0000000000000276 R10: ffffa0bc754e9b40 R11: ffffa0bc330f6400 R12: 0000000000002080 R13: ffffe36341fff700 R14: 0000000000080000 R15: ffffa0bc330f6400 FS: 00007f0ec1ea5740(0000) GS:ffffa0bc7db00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000020d8 CR3: 0000000077d68000 CR4: 00000000000006e0 Call Trace: page_idle_bitmap_write+0x8c/0x140 sysfs_kf_bin_write+0x5c/0x70 kernfs_fop_write+0x12e/0x1b0 __vfs_write+0x1b/0x40 vfs_write+0xab/0x1b0 ksys_write+0x55/0xc0 __x64_sys_write+0x1a/0x20 do_syscall_64+0x5a/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Link: http://lkml.kernel.org/r/20190618124352.28307-1-colin.king@canonical.com Fixes: 33c3fc7 ("mm: introduce idle page tracking") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d0a255e upstream. A deadlock with this stacktrace was observed. The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio shrinker and the shrinker depends on I/O completion in the dm-bufio subsystem. In order to fix the deadlock (and other similar ones), we set the flag PF_MEMALLOC_NOIO at loop thread entry. PID: 474 TASK: ffff8813e11f4600 CPU: 10 COMMAND: "kswapd0" #0 [ffff8813dedfb938] __schedule at ffffffff8173f405 #1 [ffff8813dedfb990] schedule at ffffffff8173fa27 #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186 #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8 #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81 #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio] #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio] #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio] #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778 #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f #13 [ffff8813dedfbec0] kthread at ffffffff810a8428 #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242 PID: 14127 TASK: ffff881455749c00 CPU: 11 COMMAND: "loop1" #0 [ffff88272f5af228] __schedule at ffffffff8173f405 #1 [ffff88272f5af280] schedule at ffffffff8173fa27 #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5 #4 [ffff88272f5af330] mutex_lock at ffffffff81742133 #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio] #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778 #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34 #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8 #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3 #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71 #12 [ffff88272f5af760] new_slab at ffffffff811f4523 #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5 #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3 #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3 #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs] #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994 #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs] #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop] #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop] #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c #23 [ffff88272f5afec0] kthread at ffffffff810a8428 #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit cf3591e upstream. Revert the commit bd293d0. The proper fix has been made available with commit d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread"). Note that the fix offered by commit bd293d0 doesn't really prevent the deadlock from occuring - if we look at the stacktrace reported by Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex - i.e. it has already successfully taken the mutex. Changing the mutex from mutex_lock to mutex_trylock won't help with deadlocks that happen afterwards. PID: 474 TASK: ffff8813e11f4600 CPU: 10 COMMAND: "kswapd0" #0 [ffff8813dedfb938] __schedule at ffffffff8173f405 #1 [ffff8813dedfb990] schedule at ffffffff8173fa27 #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186 #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8 #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81 #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio] #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio] #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio] #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778 #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f #13 [ffff8813dedfbec0] kthread at ffffffff810a8428 #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Fixes: bd293d0 ("dm bufio: fix deadlock with loop device") Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread") Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 314eed3 upstream. When running on a system with >512MB RAM with a 32-bit kernel built with: CONFIG_DEBUG_VIRTUAL=y CONFIG_HIGHMEM=y CONFIG_HARDENED_USERCOPY=y all execve()s will fail due to argv copying into kmap()ed pages, and on usercopy checking the calls ultimately of virt_to_page() will be looking for "bad" kmap (highmem) pointers due to CONFIG_DEBUG_VIRTUAL=y: ------------[ cut here ]------------ kernel BUG at ../arch/x86/mm/physaddr.c:83! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc8 #6 Hardware name: Dell Inc. Inspiron 1318/0C236D, BIOS A04 01/15/2009 EIP: __phys_addr+0xaf/0x100 ... Call Trace: __check_object_size+0xaf/0x3c0 ? __might_sleep+0x80/0xa0 copy_strings+0x1c2/0x370 copy_strings_kernel+0x2b/0x40 __do_execve_file+0x4ca/0x810 ? kmem_cache_alloc+0x1c7/0x370 do_execve+0x1b/0x20 ... The check is from arch/x86/mm/physaddr.c: VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn); Due to the kmap() in fs/exec.c: kaddr = kmap(kmapped_page); ... if (copy_from_user(kaddr+offset, str, bytes_to_copy)) ... Now we can fetch the correct page to avoid the pfn check. In both cases, hardened usercopy will need to walk the page-span checker (if enabled) to do sanity checking. Reported-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Fixes: f5509cc ("mm: Hardened usercopy") Cc: Matthew Wilcox <willy@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://lore.kernel.org/r/201909171056.7F2FFD17@keescook Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 443f2d5 upstream. Observe a segmentation fault when 'perf stat' is asked to repeat forever with the interval option. Without fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.000211692 3,13,89,82,34,157 cycles 10.000380119 1,53,98,52,22,294 cycles 10.040467280 17,16,79,265 cycles Segmentation fault This problem was only observed when we use forever option aka -r 0 and works with limited repeats. Calling print_counter with ts being set to NULL, is not a correct option when interval is set. Hence avoid print_counter(NULL,..) if interval is set. With fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.019866622 3,15,14,43,08,697 cycles 10.039865756 3,15,16,31,95,261 cycles 10.059950628 1,26,05,47,158 cycles 5.009902655 3,14,52,62,33,932 cycles 10.019880228 3,14,52,22,89,154 cycles 10.030543876 66,90,18,333 cycles 5.009848281 3,14,51,98,25,437 cycles 10.029854402 3,15,14,93,04,918 cycles 5.009834177 3,14,51,95,92,316 cycles Committer notes: Did the 'git bisect' to find the cset introducing the problem to add the Fixes tag below, and at that time the problem reproduced as: (gdb) run stat -r0 -I500 sleep 1 <SNIP> Program received signal SIGSEGV, Segmentation fault. print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 866 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep); (gdb) bt #0 print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 #1 0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938 #2 0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411 #3 0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370 #4 0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429 #5 0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473 #6 0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588 (gdb) Mostly the same as just before this patch: Program received signal SIGSEGV, Segmentation fault. 0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 964 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep); (gdb) bt #0 0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 #1 0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670) at util/stat-display.c:1172 #2 0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656 #3 0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960 #4 0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310 #5 0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362 #6 0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406 #7 0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531 (gdb) Fixes: d4f63a4 ("perf stat: Introduce print_counters function") Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v4.2+ Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 0216234 ] We release wrong pointer on error path in cpu_cache_level__read function, leading to segfault: (gdb) r record ls Starting program: /root/perf/tools/perf/perf record ls ... [ perf record: Woken up 1 times to write data ] double free or corruption (out) Thread 1 "perf" received signal SIGABRT, Aborted. 0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6 (gdb) bt #0 0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6 #1 0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6 #2 0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6 #3 0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6 #4 0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6 #5 0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc.. #6 0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac.. #7 0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz.. ... Releasing the proper pointer. Fixes: 720e98b ("perf tools: Add perf data cache feature") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org: # v4.6+ Link: http://lore.kernel.org/lkml/20190912105235.10689-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

…span() commit 7ce700b upstream. Let's limit shrinking to !ZONE_DEVICE so we can fix the current code. We should never try to touch the memmap of offline sections where we could have uninitialized memmaps and could trigger BUGs when calling page_to_nid() on poisoned pages. There is no reliable way to distinguish an uninitialized memmap from an initialized memmap that belongs to ZONE_DEVICE, as we don't have anything like SECTION_IS_ONLINE we can use similar to pfn_to_online_section() for !ZONE_DEVICE memory. E.g., set_zone_contiguous() similarly relies on pfn_to_online_section() and will therefore never set a ZONE_DEVICE zone consecutive. Stopping to shrink the ZONE_DEVICE therefore results in no observable changes, besides /proc/zoneinfo indicating different boundaries - something we can totally live with. Before commit d0dc12e ("mm/memory_hotplug: optimize memory hotplug"), the memmap was initialized with 0 and the node with the right value. So the zone might be wrong but not garbage. After that commit, both the zone and the node will be garbage when touching uninitialized memmaps. Toshiki reported a BUG (race between delayed initialization of ZONE_DEVICE memmaps without holding the memory hotplug lock and concurrent zone shrinking). https://lkml.org/lkml/2019/11/14/1040 "Iteration of create and destroy namespace causes the panic as below: kernel BUG at mm/page_alloc.c:535! CPU: 7 PID: 2766 Comm: ndctl Not tainted 5.4.0-rc4 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014 RIP: 0010:set_pfnblock_flags_mask+0x95/0xf0 Call Trace: memmap_init_zone_device+0x165/0x17c memremap_pages+0x4c1/0x540 devm_memremap_pages+0x1d/0x60 pmem_attach_disk+0x16b/0x600 [nd_pmem] nvdimm_bus_probe+0x69/0x1c0 really_probe+0x1c2/0x3e0 driver_probe_device+0xb4/0x100 device_driver_attach+0x4f/0x60 bind_store+0xc9/0x110 kernfs_fop_write+0x116/0x190 vfs_write+0xa5/0x1a0 ksys_write+0x59/0xd0 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 While creating a namespace and initializing memmap, if you destroy the namespace and shrink the zone, it will initialize the memmap outside the zone and trigger VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page) in set_pfnblock_flags_mask()." This BUG is also mitigated by this commit, where we for now stop to shrink the ZONE_DEVICE zone until we can do it in a safe and clean way. Link: http://lkml.kernel.org/r/20191006085646.5768-5-david@redhat.com Fixes: f1dd2cd ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e] Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reported-by: Toshiki Fukasawa <t-fukasawa@vx.jp.nec.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Damian Tometzki <damian.tometzki@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@lca.pw> Cc: Rich Felker <dalias@libc.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Steve Capper <steve.capper@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Yu Zhao <yuzhao@google.com> Cc: <stable@vger.kernel.org> [4.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

…ases [ Upstream commit cf6acb7 ] v4l2-compliance fails with this message: fail: v4l2-test-buffers.cpp(691): ret == 0 fail: v4l2-test-buffers.cpp(974): captureBufs(node, q, m2m_q, frame_count, true) test MMAP: FAIL This caused the following Kernel Warning: WARNING: CPU: 0 PID: 961 at drivers/media/v4l2-core/videobuf2-core.c:1658 __vb2_queue_cancel+0x174/0x1d8 ... CPU: 0 PID: 961 Comm: v4l2-compliance Not tainted 4.14.62-01720-g20ecd717e87a #6 Hardware name: Generic DRA72X (Flattened Device Tree) Backtrace: [<c020b5bc>] (dump_backtrace) from [<c020b8a0>] (show_stack+0x18/0x1c) r7:00000009 r6:60070013 r5:00000000 r4:c1053824 [<c020b888>] (show_stack) from [<c09232e8>] (dump_stack+0x90/0xa4) [<c0923258>] (dump_stack) from [<c022b740>] (__warn+0xec/0x104) r7:00000009 r6:c0c0ad50 r5:00000000 r4:00000000 [<c022b654>] (__warn) from [<c022b810>] (warn_slowpath_null+0x28/0x30) r9:00000008 r8:00000000 r7:eced4808 r6:edbc9bac r5:eced4844 r4:eced4808 [<c022b7e8>] (warn_slowpath_null) from [<c0726f48>] (__vb2_queue_cancel+0x174/0x1d8) [<c0726dd4>] (__vb2_queue_cancel) from [<c0727648>] (vb2_core_queue_release+0x20/0x40) r10:ecc7bd70 r9:00000008 r8:00000000 r7:edb73010 r6:edbc9bac r5:eced4844 r4:eced4808 r3:00000004 [<c0727628>] (vb2_core_queue_release) from [<c0729528>] (vb2_queue_release+0x10/0x14) r5:edbc9810 r4:eced4800 [<c0729518>] (vb2_queue_release) from [<c0724d08>] (v4l2_m2m_ctx_release+0x1c/0x30) [<c0724cec>] (v4l2_m2m_ctx_release) from [<bf0e8f28>] (vpe_release+0x74/0xb0 [ti_vpe]) r5:edbc9810 r4:ed67a400 [<bf0e8eb4>] (vpe_release [ti_vpe]) from [<c070fccc>] (v4l2_release+0x3c/0x80) r7:edb73010 r6:ed176aa0 r5:edbc9868 r4:ed5119c0 [<c070fc90>] (v4l2_release) from [<c033cf1c>] (__fput+0x8c/0x1dc) r5:ecc7bd70 r4:ed5119c0 [<c033ce90>] (__fput) from [<c033d0cc>] (____fput+0x10/0x14) r10:00000000 r9:ed5119c0 r8:ece392d0 r7:c1059544 r6:ece38d80 r5:ece392b4 r4:00000000 [<c033d0bc>] (____fput) from [<c0246e00>] (task_work_run+0x98/0xb8) [<c0246d68>] (task_work_run) from [<c022f1d8>] (do_exit+0x170/0xa80) r9:ece351fc r8:00000000 r7:ecde3f58 r6:ffffe000 r5:ece351c0 r4:ece38d80 [<c022f068>] (do_exit) from [<c022fb6c>] (do_group_exit+0x48/0xc4) r7:000000f8 [<c022fb24>] (do_group_exit) from [<c022fc00>] (__wake_up_parent+0x0/0x28) r7:000000f8 r6:b6c6a798 r5:00000001 r4:00000001 [<c022fbe8>] (SyS_exit_group) from [<c0207c80>] (ret_fast_syscall+0x0/0x4c) These warnings are caused by buffers which not properly cleaned up/release during an abort use case. In the abort cases the VPDMA desc buffers would still be mapped and the in-flight VB2 buffers would not be released properly causing a kernel warning from being generated by the videobuf2-core level. Signed-off-by: Benoit Parrot <bparrot@ti.com> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>

…_clear_bit [ Upstream commit fadcbd2 ] We need to move "spin_lock_irq(&bitmap->counts.lock)" before unmap previous storage, otherwise panic like belows could happen as follows. [ 902.353802] sdl: detected capacity change from 1077936128 to 3221225472 [ 902.616948] general protection fault: 0000 [#1] SMP [snip] [ 902.618588] CPU: 12 PID: 33698 Comm: md0_raid1 Tainted: G O 4.14.144-1-pserver #4.14.144-1.1~deb10 [ 902.618870] Hardware name: Supermicro SBA-7142G-T4/BHQGE, BIOS 3.00 10/24/2012 [ 902.619120] task: ffff9ae1860fc600 task.stack: ffffb52e4c704000 [ 902.619301] RIP: 0010:bitmap_file_clear_bit+0x90/0xd0 [md_mod] [ 902.619464] RSP: 0018:ffffb52e4c707d28 EFLAGS: 00010087 [ 902.619626] RAX: ffe8008b0d061000 RBX: ffff9ad078c87300 RCX: 0000000000000000 [ 902.619792] RDX: ffff9ad986341868 RSI: 0000000000000803 RDI: ffff9ad078c87300 [ 902.619986] RBP: ffff9ad0ed7a8000 R08: 0000000000000000 R09: 0000000000000000 [ 902.620154] R10: ffffb52e4c707ec0 R11: ffff9ad987d1ed44 R12: ffff9ad0ed7a8360 [ 902.620320] R13: 0000000000000003 R14: 0000000000060000 R15: 0000000000000800 [ 902.620487] FS: 0000000000000000(0000) GS:ffff9ad987d00000(0000) knlGS:0000000000000000 [ 902.620738] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 902.620901] CR2: 000055ff12aecec0 CR3: 0000001005207000 CR4: 00000000000406e0 [ 902.621068] Call Trace: [ 902.621256] bitmap_daemon_work+0x2dd/0x360 [md_mod] [ 902.621429] ? find_pers+0x70/0x70 [md_mod] [ 902.621597] md_check_recovery+0x51/0x540 [md_mod] [ 902.621762] raid1d+0x5c/0xeb0 [raid1] [ 902.621939] ? try_to_del_timer_sync+0x4d/0x80 [ 902.622102] ? del_timer_sync+0x35/0x40 [ 902.622265] ? schedule_timeout+0x177/0x360 [ 902.622453] ? call_timer_fn+0x130/0x130 [ 902.622623] ? find_pers+0x70/0x70 [md_mod] [ 902.622794] ? md_thread+0x94/0x150 [md_mod] [ 902.622959] md_thread+0x94/0x150 [md_mod] [ 902.623121] ? wait_woken+0x80/0x80 [ 902.623280] kthread+0x119/0x130 [ 902.623437] ? kthread_create_on_node+0x60/0x60 [ 902.623600] ret_from_fork+0x22/0x40 [ 902.624225] RIP: bitmap_file_clear_bit+0x90/0xd0 [md_mod] RSP: ffffb52e4c707d28 Because mdadm was running on another cpu to do resize, so bitmap_resize was called to replace bitmap as below shows. PID: 38801 TASK: ffff9ad074a90e00 CPU: 0 COMMAND: "mdadm" [exception RIP: queued_spin_lock_slowpath+56] [snip] -- <NMI exception stack> -- #5 [ffffb52e60f17c58] queued_spin_lock_slowpath at ffffffff9c0b27b8 #6 [ffffb52e60f17c58] bitmap_resize at ffffffffc0399877 [md_mod] #7 [ffffb52e60f17d30] raid1_resize at ffffffffc0285bf9 [raid1] #8 [ffffb52e60f17d50] update_size at ffffffffc038a31a [md_mod] #9 [ffffb52e60f17d70] md_ioctl at ffffffffc0395ca4 [md_mod] And the procedure to keep resize bitmap safe is allocate new storage space, then quiesce, copy bits, replace bitmap, and re-start. However the daemon (bitmap_daemon_work) could happen even the array is quiesced, which means when bitmap_file_clear_bit is triggered by raid1d, then it thinks it should be fine to access store->filemap since counts->lock is held, but resize could change the storage without the protection of the lock. Cc: Jack Wang <jinpu.wang@cloud.ionos.com> Cc: NeilBrown <neilb@suse.com> Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

… session [ Upstream commit e9d3009 ] The iSCSI target driver is the only target driver that does not wait for ongoing commands to finish before freeing a session. Make the iSCSI target driver wait for ongoing commands to finish before freeing a session. This patch fixes the following KASAN complaint: BUG: KASAN: use-after-free in __lock_acquire+0xb1a/0x2710 Read of size 8 at addr ffff8881154eca70 by task kworker/0:2/247 CPU: 0 PID: 247 Comm: kworker/0:2 Not tainted 5.4.0-rc1-dbg+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Workqueue: target_completion target_complete_ok_work [target_core_mod] Call Trace: dump_stack+0x8a/0xd6 print_address_description.constprop.0+0x40/0x60 __kasan_report.cold+0x1b/0x33 kasan_report+0x16/0x20 __asan_load8+0x58/0x90 __lock_acquire+0xb1a/0x2710 lock_acquire+0xd3/0x200 _raw_spin_lock_irqsave+0x43/0x60 target_release_cmd_kref+0x162/0x7f0 [target_core_mod] target_put_sess_cmd+0x2e/0x40 [target_core_mod] lio_check_stop_free+0x12/0x20 [iscsi_target_mod] transport_cmd_check_stop_to_fabric+0xd8/0xe0 [target_core_mod] target_complete_ok_work+0x1b0/0x790 [target_core_mod] process_one_work+0x549/0xa40 worker_thread+0x7a/0x5d0 kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 Allocated by task 889: save_stack+0x23/0x90 __kasan_kmalloc.constprop.0+0xcf/0xe0 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0xf6/0x360 transport_alloc_session+0x29/0x80 [target_core_mod] iscsi_target_login_thread+0xcd6/0x18f0 [iscsi_target_mod] kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 Freed by task 1025: save_stack+0x23/0x90 __kasan_slab_free+0x13a/0x190 kasan_slab_free+0x12/0x20 kmem_cache_free+0x146/0x400 transport_free_session+0x179/0x2f0 [target_core_mod] transport_deregister_session+0x130/0x180 [target_core_mod] iscsit_close_session+0x12c/0x350 [iscsi_target_mod] iscsit_logout_post_handler+0x136/0x380 [iscsi_target_mod] iscsit_response_queue+0x8de/0xbe0 [iscsi_target_mod] iscsi_target_tx_thread+0x27f/0x370 [iscsi_target_mod] kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 The buggy address belongs to the object at ffff8881154ec9c0 which belongs to the cache se_sess_cache of size 352 The buggy address is located 176 bytes inside of 352-byte region [ffff8881154ec9c0, ffff8881154ecb20) The buggy address belongs to the page: page:ffffea0004553b00 refcount:1 mapcount:0 mapping:ffff888101755400 index:0x0 compound_mapcount: 0 flags: 0x2fff000000010200(slab|head) raw: 2fff000000010200 dead000000000100 dead000000000122 ffff888101755400 raw: 0000000000000000 0000000080130013 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881154ec900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881154ec980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8881154eca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881154eca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881154ecb00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc Cc: Mike Christie <mchristi@redhat.com> Link: https://lore.kernel.org/r/20191113220508.198257-3-bvanassche@acm.org Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

…erycap commit 5d2e73a upstream. SyzKaller hit the null pointer deref while reading from uninitialized udev->product in zr364xx_vidioc_querycap(). ================================================================== BUG: KASAN: null-ptr-deref in read_word_at_a_time+0xe/0x20 include/linux/compiler.h:274 Read of size 1 at addr 0000000000000000 by task v4l_id/5287 CPU: 1 PID: 5287 Comm: v4l_id Not tainted 5.1.0-rc3-319004-g43151d6 #6 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xe8/0x16e lib/dump_stack.c:113 kasan_report.cold+0x5/0x3c mm/kasan/report.c:321 read_word_at_a_time+0xe/0x20 include/linux/compiler.h:274 strscpy+0x8a/0x280 lib/string.c:207 zr364xx_vidioc_querycap+0xb5/0x210 drivers/media/usb/zr364xx/zr364xx.c:706 v4l_querycap+0x12b/0x340 drivers/media/v4l2-core/v4l2-ioctl.c:1062 __video_do_ioctl+0x5bb/0xb40 drivers/media/v4l2-core/v4l2-ioctl.c:2874 video_usercopy+0x44e/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3056 v4l2_ioctl+0x14e/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:364 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xced/0x12f0 fs/ioctl.c:696 ksys_ioctl+0xa0/0xc0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:718 do_syscall_64+0xcf/0x4f0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f3b56d8b347 Code: 90 90 90 48 8b 05 f1 fa 2a 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 90 90 90 90 90 90 90 90 90 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c1 fa 2a 00 31 d2 48 29 c2 64 RSP: 002b:00007ffe005d5d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f3b56d8b347 RDX: 00007ffe005d5d70 RSI: 0000000080685600 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400884 R13: 00007ffe005d5ec0 R14: 0000000000000000 R15: 0000000000000000 ================================================================== For this device udev->product is not initialized and accessing it causes a NULL pointer deref. The fix is to check for NULL before strscpy() and copy empty string, if product is NULL Reported-by: syzbot+66010012fd4c531a1a96@syzkaller.appspotmail.com Signed-off-by: Vandana BN <bnvandana@gmail.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> [bwh: Backported to 4.19: This function uses strlcpy() instead of strscpy()] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

…is valid commit 2fe2021 upstream. When booting with amd_iommu=off, the following WARNING message appears: AMD-Vi: AMD IOMMU disabled on kernel command-line ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/workqueue.c:2772 flush_workqueue+0x42e/0x450 Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc3-amd-iommu #6 Hardware name: Lenovo ThinkSystem SR655-2S/7D2WRCZ000, BIOS D8E101L-1.00 12/05/2019 RIP: 0010:flush_workqueue+0x42e/0x450 Code: ff 0f 0b e9 7a fd ff ff 4d 89 ef e9 33 fe ff ff 0f 0b e9 7f fd ff ff 0f 0b e9 bc fd ff ff 0f 0b e9 a8 fd ff ff e8 52 2c fe ff <0f> 0b 31 d2 48 c7 c6 e0 88 c5 95 48 c7 c7 d8 ad f0 95 e8 19 f5 04 Call Trace: kmem_cache_destroy+0x69/0x260 iommu_go_to_state+0x40c/0x5ab amd_iommu_prepare+0x16/0x2a irq_remapping_prepare+0x36/0x5f enable_IR_x2apic+0x21/0x172 default_setup_apic_routing+0x12/0x6f apic_intr_mode_init+0x1a1/0x1f1 x86_late_time_init+0x17/0x1c start_kernel+0x480/0x53f secondary_startup_64+0xb6/0xc0 ---[ end trace 30894107c3749449 ]--- x2apic: IRQ remapping doesn't support X2APIC mode x2apic disabled The warning is caused by the calling of 'kmem_cache_destroy()' in free_iommu_resources(). Here is the call path: free_iommu_resources kmem_cache_destroy flush_memcg_workqueue flush_workqueue The root cause is that the IOMMU subsystem runs before the workqueue subsystem, which the variable 'wq_online' is still 'false'. This leads to the statement 'if (WARN_ON(!wq_online))' in flush_workqueue() is 'true'. Since the variable 'memcg_kmem_cache_wq' is not allocated during the time, it is unnecessary to call flush_memcg_workqueue(). This prevents the WARNING message triggered by flush_workqueue(). Link: http://lkml.kernel.org/r/20200103085503.1665-1-ahuang12@lenovo.com Fixes: 92ee383 ("mm: fix race between kmem_cache destroy, create and deactivate") Signed-off-by: Adrian Huang <ahuang12@lenovo.com> Reported-by: Xiaochun Lee <lixc17@lenovo.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 5eed6f1 ] Commit 9b6f7e1 ("mm: rework memcg kernel stack accounting") will result in fork failing if allocating a kernel stack for a task in dup_task_struct exceeds the kernel memory allowance for that cgroup. Unfortunately, it also results in a crash. This is due to the code jumping to free_stack and calling free_thread_stack when the memcg kernel stack charge fails, but without tsk->stack pointing at the freshly allocated stack. This in turn results in the vfree_atomic in free_thread_stack oopsing with a backtrace like this: #5 [ffffc900244efc88] die at ffffffff8101f0ab #6 [ffffc900244efcb8] do_general_protection at ffffffff8101cb86 #7 [ffffc900244efce0] general_protection at ffffffff818ff082 [exception RIP: llist_add_batch+7] RIP: ffffffff8150d487 RSP: ffffc900244efd98 RFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88085ef55980 RCX: 0000000000000000 RDX: ffff88085ef55980 RSI: 343834343531203a RDI: 343834343531203a RBP: ffffc900244efd98 R8: 0000000000000001 R9: ffff8808578c3600 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88029f6c21c0 R13: 0000000000000286 R14: ffff880147759b00 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #8 [ffffc900244efda0] vfree_atomic at ffffffff811df2c7 #9 [ffffc900244efdb8] copy_process at ffffffff81086e37 #10 [ffffc900244efe98] _do_fork at ffffffff810884e0 #11 [ffffc900244eff10] sys_vfork at ffffffff810887ff #12 [ffffc900244eff20] do_syscall_64 at ffffffff81002a43 RIP: 000000000049b948 RSP: 00007ffcdb307830 RFLAGS: 00000246 RAX: ffffffffffffffda RBX: 0000000000896030 RCX: 000000000049b948 RDX: 0000000000000000 RSI: 00007ffcdb307790 RDI: 00000000005d7421 RBP: 000000000067370f R8: 00007ffcdb3077b0 R9: 000000000001ed00 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000040 R13: 000000000000000f R14: 0000000000000000 R15: 000000000088d018 ORIG_RAX: 000000000000003a CS: 0033 SS: 002b The simplest fix is to assign tsk->stack right where it is allocated. Link: http://lkml.kernel.org/r/20181214231726.7ee4843c@imladris.surriel.com Fixes: 9b6f7e1 ("mm: rework memcg kernel stack accounting") Signed-off-by: Rik van Riel <riel@surriel.com> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 96bf313ecb33567af4cb53928b0c951254a02759 ] There exists a deadlock with range_cyclic that has existed forever. If we loop around with a bio already built we could deadlock with a writer who has the page locked that we're attempting to write but is waiting on a page in our bio to be written out. The task traces are as follows PID: 1329874 TASK: ffff889ebcdf3800 CPU: 33 COMMAND: "kworker/u113:5" #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3 #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42 #3 [ffffc900297bb708] __lock_page at ffffffff811f145b #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502 #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684 #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0 #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2 #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd PID: 2167901 TASK: ffff889dc6a59c00 CPU: 14 COMMAND: "aio-dio-invalid" #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3 #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42 #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6 #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7 #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359 #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933 #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8 #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032 I used drgn to find the respective pages we were stuck on page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901 page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874 As you can see the kworker is waiting for bit 0 (PG_locked) on index 7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index 8148. aio-dio-invalid has 7680, and the kworker epd looks like the following crash> struct extent_page_data ffffc900297bbbb0 struct extent_page_data { bio = 0xffff889f747ed830, tree = 0xffff889eed6ba448, extent_locked = 0, sync_io = 0 } Probably worth mentioning as well that it waits for writeback of the page to complete while holding a lock on it (at prepare_pages()). Using drgn I walked the bio pages looking for page 0xffffea00fbfc7500 which is the one we're waiting for writeback on bio = Object(prog, 'struct bio', address=0xffff889f747ed830) for i in range(0, bio.bi_vcnt.value_()): bv = bio.bi_io_vec[i] if bv.bv_page.value_() == 0xffffea00fbfc7500: print("FOUND IT") which validated what I suspected. The fix for this is simple, flush the epd before we loop back around to the beginning of the file during writeout. Fixes: b293f02 ("Btrfs: Add writepages support") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 1b6a51e ] The req->body should be updated before req->state is updated and the order should be guaranteed by a barrier. Otherwise, read_reply() might return req->body = NULL. Below is sample callstack when the issue is reproduced on purpose by reordering the updates of req->body and req->state and adding delay in code between updates of req->state and req->body. [ 22.356105] general protection fault: 0000 [#1] SMP PTI [ 22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6 [ 22.366727] Hardware name: Xen HVM domU, BIOS ... [ 22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 ... ... [ 22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246 [ 22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000 [ 22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d [ 22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd [ 22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000 [ 22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000 [ 22.423726] FS: 0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000 [ 22.429898] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0 [ 22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 22.450342] Call Trace: [ 22.452509] simple_strtoull+0x27/0x70 [ 22.455572] xenbus_transaction_start+0x31/0x50 [ 22.459104] netback_changed+0x76c/0xcc1 [xen_netfront] [ 22.463279] ? find_watch+0x40/0x40 [ 22.466156] xenwatch_thread+0xb4/0x150 [ 22.469309] ? wait_woken+0x80/0x80 [ 22.472198] kthread+0x10e/0x130 [ 22.474925] ? kthread_park+0x80/0x80 [ 22.477946] ret_from_fork+0x35/0x40 [ 22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront [ 22.486783] ---[ end trace a9222030a747c3f7 ]--- [ 22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 The virt_rmb() is added in the 'true' path of test_reply(). The "while" is changed to "do while" so that test_reply() is used as a read memory barrier. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com Reviewed-by: Julien Grall <jgrall@amazon.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit a866759 ] This reverts commit 64e62bd. This commit ends up causing some lockdep splats due to trying to grab the payload lock while holding the mgr's lock: [ 54.010099] [ 54.011765] ====================================================== [ 54.018670] WARNING: possible circular locking dependency detected [ 54.025577] 5.5.0-rc6-02274-g77381c23ee63 #47 Not tainted [ 54.031610] ------------------------------------------------------ [ 54.038516] kworker/1:6/1040 is trying to acquire lock: [ 54.044354] ffff888272af3228 (&mgr->payload_lock){+.+.}, at: drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4 [ 54.054957] [ 54.054957] but task is already holding lock: [ 54.061473] ffff888272af3060 (&mgr->lock){+.+.}, at: drm_dp_mst_topology_mgr_set_mst+0x3c/0x2e4 [ 54.071193] [ 54.071193] which lock already depends on the new lock. [ 54.071193] [ 54.080334] [ 54.080334] the existing dependency chain (in reverse order) is: [ 54.088697] [ 54.088697] -> #1 (&mgr->lock){+.+.}: [ 54.094440] __mutex_lock+0xc3/0x498 [ 54.099015] drm_dp_mst_topology_get_port_validated+0x25/0x80 [ 54.106018] drm_dp_update_payload_part1+0xa2/0x2e2 [ 54.112051] intel_mst_pre_enable_dp+0x144/0x18f [ 54.117791] intel_encoders_pre_enable+0x63/0x70 [ 54.123532] hsw_crtc_enable+0xa1/0x722 [ 54.128396] intel_update_crtc+0x50/0x194 [ 54.133455] skl_commit_modeset_enables+0x40c/0x540 [ 54.139485] intel_atomic_commit_tail+0x5f7/0x130d [ 54.145418] intel_atomic_commit+0x2c8/0x2d8 [ 54.150770] drm_atomic_helper_set_config+0x5a/0x70 [ 54.156801] drm_mode_setcrtc+0x2ab/0x833 [ 54.161862] drm_ioctl+0x2e5/0x424 [ 54.166242] vfs_ioctl+0x21/0x2f [ 54.170426] do_vfs_ioctl+0x5fb/0x61e [ 54.175096] ksys_ioctl+0x55/0x75 [ 54.179377] __x64_sys_ioctl+0x1a/0x1e [ 54.184146] do_syscall_64+0x5c/0x6d [ 54.188721] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.194946] [ 54.194946] -> #0 (&mgr->payload_lock){+.+.}: [ 54.201463] [ 54.201463] other info that might help us debug this: [ 54.201463] [ 54.210410] Possible unsafe locking scenario: [ 54.210410] [ 54.217025] CPU0 CPU1 [ 54.222082] ---- ---- [ 54.227138] lock(&mgr->lock); [ 54.230643] lock(&mgr->payload_lock); [ 54.237742] lock(&mgr->lock); [ 54.244062] lock(&mgr->payload_lock); [ 54.248346] [ 54.248346] *** DEADLOCK *** [ 54.248346] [ 54.254959] 7 locks held by kworker/1:6/1040: [ 54.259822] #0: ffff888275c4f528 ((wq_completion)events){+.+.}, at: worker_thread+0x455/0x6e2 [ 54.269451] #1: ffffc9000119beb0 ((work_completion)(&(&dev_priv->hotplug.hotplug_work)->work)){+.+.}, at: worker_thread+0x455/0x6e2 [ 54.282768] #2: ffff888272a403f0 (&dev->mode_config.mutex){+.+.}, at: i915_hotplug_work_func+0x4b/0x2be [ 54.293368] #3: ffffffff824fc6c0 (drm_connector_list_iter){.+.+}, at: i915_hotplug_work_func+0x17e/0x2be [ 54.304061] #4: ffffc9000119bc58 (crtc_ww_class_acquire){+.+.}, at: drm_helper_probe_detect_ctx+0x40/0xfd [ 54.314855] #5: ffff888272a40470 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_lock+0x74/0xe2 [ 54.324385] #6: ffff888272af3060 (&mgr->lock){+.+.}, at: drm_dp_mst_topology_mgr_set_mst+0x3c/0x2e4 [ 54.334597] [ 54.334597] stack backtrace: [ 54.339464] CPU: 1 PID: 1040 Comm: kworker/1:6 Not tainted 5.5.0-rc6-02274-g77381c23ee63 #47 [ 54.348893] Hardware name: Google Fizz/Fizz, BIOS Google_Fizz.10139.39.0 01/04/2018 [ 54.357451] Workqueue: events i915_hotplug_work_func [ 54.362995] Call Trace: [ 54.365724] dump_stack+0x71/0x9c [ 54.369427] check_noncircular+0x91/0xbc [ 54.373809] ? __lock_acquire+0xc9e/0xf66 [ 54.378286] ? __lock_acquire+0xc9e/0xf66 [ 54.382763] ? lock_acquire+0x175/0x1ac [ 54.387048] ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4 [ 54.393177] ? __mutex_lock+0xc3/0x498 [ 54.397362] ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4 [ 54.403492] ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4 [ 54.409620] ? drm_dp_dpcd_access+0xd9/0x101 [ 54.414390] ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4 [ 54.420517] ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4 [ 54.426645] ? intel_digital_port_connected+0x34d/0x35c [ 54.432482] ? intel_dp_detect+0x227/0x44e [ 54.437056] ? ww_mutex_lock+0x49/0x9a [ 54.441242] ? drm_helper_probe_detect_ctx+0x75/0xfd [ 54.446789] ? intel_encoder_hotplug+0x4b/0x97 [ 54.451752] ? intel_ddi_hotplug+0x61/0x2e0 [ 54.456423] ? mark_held_locks+0x53/0x68 [ 54.460803] ? _raw_spin_unlock_irqrestore+0x3a/0x51 [ 54.466347] ? lockdep_hardirqs_on+0x187/0x1a4 [ 54.471310] ? drm_connector_list_iter_next+0x89/0x9a [ 54.476953] ? i915_hotplug_work_func+0x206/0x2be [ 54.482208] ? worker_thread+0x4d5/0x6e2 [ 54.486587] ? worker_thread+0x455/0x6e2 [ 54.490966] ? queue_work_on+0x64/0x64 [ 54.495151] ? kthread+0x1e9/0x1f1 [ 54.498946] ? queue_work_on+0x64/0x64 [ 54.503130] ? kthread_unpark+0x5e/0x5e [ 54.507413] ? ret_from_fork+0x3a/0x50 The proper fix for this is probably cleanup the VCPI allocations when we're enabling the topology, or on the first payload allocation. For now though, let's just revert. Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: 64e62bd ("drm/dp_mst: Remove VCPI while disabling topology mgr") Cc: Sean Paul <sean@poorly.run> Cc: Wayne Lin <Wayne.Lin@amd.com> Reviewed-by: Sean Paul <sean@poorly.run> Link: https://patchwork.freedesktop.org/patch/msgid/20200117205149.97262-1-lyude@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>

Matthew Garrett and others added 21 commits January 11, 2016 21:33

efi: Make EFI_SECURE_BOOT_SIG_ENFORCE depend on EFI

9bfe6c0

The functionality of the config option is dependent upon the platform being UEFI based. Reflect this in the config deps. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>

efi: Add EFI_SECURE_BOOT bit

1b43518

UEFI machines can be booted in Secure Boot mode. Add a EFI_SECURE_BOOT bit for use with efi_enabled. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>

Overlayfs: Use copy-up security hooks

2e1d35f

Use the copy-up security hooks previously provided to allow an LSM to adjust the security on a newly created copy and to filter the xattrs copied to that file copy. Signed-off-by: David Howells <dhowells@redhat.com>

overlayfs: use a minimal buffer in ovl_copy_xattr

116f798

Rather than always allocating the high-order XATTR_SIZE_MAX buffer which is costly and prone to failure, only allocate what is needed and realloc if necessary. Fixes coreos/bugs#489

crawford changed the title *: backport changes from v4.3.3-coreos *: rebase changes from v4.3.3-coreos Jan 12, 2016

crawford mentioned this pull request Jan 12, 2016

coreos-{kernel/sources}: bump to v4.4-coreos coreos/coreos-overlay#1718

Merged

crawford added a commit that referenced this pull request Jan 12, 2016

Merge pull request #6 from crawford/v4.4-coreos

2c15b9d

*: rebase changes from v4.3.3-coreos

crawford merged commit 2c15b9d into coreos:v4.4-coreos Jan 12, 2016

crawford deleted the v4.4-coreos branch January 12, 2016 21:39

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*: rebase changes from v4.3.3-coreos #6

*: rebase changes from v4.3.3-coreos #6

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*: rebase changes from v4.3.3-coreos #6

*: rebase changes from v4.3.3-coreos #6

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