ext4: correct grp validation in ext4_mb_good_group

[ Upstream commit a9ce5993a0 ]

Group corruption check will access memory of grp and will trigger kernel
crash if grp is NULL. So do NULL check before corruption check.

Fixes: 5354b2af34 ("ext4: allow ext4_get_group_info() to fail")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kemeng Shi 2023-08-01 22:31:55 +08:00 committed by Greg Kroah-Hartman
parent 2aefe3ae09
commit 245759d987

View file

@ -2103,7 +2103,7 @@ static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
BUG_ON(cr < 0 || cr >= 4);
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp) || !grp))
if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
return false;
free = grp->bb_free;