From fd442a702e2bb8309a695b3e11de7917e693849d Mon Sep 17 00:00:00 2001 From: Alexander Potapenko <glider@google.com> Date: Mon, 21 Nov 2022 12:21:30 +0100 Subject: [PATCH] fs: ext4: initialize fsdata in pagecache_write() commit 956510c0c7439e90b8103aaeaf4da92878c622f0 upstream. When aops->write_begin() does not initialize fsdata, KMSAN reports an error passing the latter to aops->write_end(). Fix this by unconditionally initializing fsdata. Cc: Eric Biggers <ebiggers@kernel.org> Fixes: c93d8f885809 ("ext4: add basic fs-verity support") Reported-by: syzbot+9767be679ef5016b6082@syzkaller.appspotmail.com Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20221121112134.407362-1-glider@google.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/ext4/verity.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c index 3c640bd7ecaeb4..30e3b65798b509 100644 --- a/fs/ext4/verity.c +++ b/fs/ext4/verity.c @@ -79,7 +79,7 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count, size_t n = min_t(size_t, count, PAGE_SIZE - offset_in_page(pos)); struct page *page; - void *fsdata; + void *fsdata = NULL; int res; res = aops->write_begin(NULL, mapping, pos, n, &page, &fsdata);