From 01bc132048cf9505ed49152cc82e583b18c5538d Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 17 Sep 2017 14:06:38 -0700 Subject: [PATCH] xfs: check _alloc_read_agf buffer pointer before using commit 10479e2dea83d4c421ad05dfc55d918aa8dfc0cd upstream. In some circumstances, _alloc_read_agf can return an error code of zero but also a null AGF buffer pointer. Check for this and jump out. Fixes-coverity-id: 1415250 Fixes-coverity-id: 1415320 Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster Signed-off-by: Greg Kroah-Hartman --- fs/xfs/libxfs/xfs_refcount.c | 4 ++++ fs/xfs/xfs_reflink.c | 2 ++ 2 files changed, 6 insertions(+) diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c index e17016163542db..d71cb63cdea367 100644 --- a/fs/xfs/libxfs/xfs_refcount.c +++ b/fs/xfs/libxfs/xfs_refcount.c @@ -1640,6 +1640,10 @@ xfs_refcount_recover_cow_leftovers( error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp); if (error) goto out_trans; + if (!agbp) { + error = -ENOMEM; + goto out_trans; + } cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, NULL); /* Find all the leftover CoW staging extents. */ diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 350fc64441b186..0015c19c745512 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -169,6 +169,8 @@ xfs_reflink_find_shared( error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); if (error) return error; + if (!agbp) + return -ENOMEM; cur = xfs_refcountbt_init_cursor(mp, NULL, agbp, agno, NULL);