6.4-stable review patch. If anyone has any objections, please let me know.
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From: Kemeng Shi shikemeng@huaweicloud.com
[ Upstream commit a9ce5993a0f5c0887c8a1b4ffa3b8046fbcfdc93 ]
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: 5354b2af3406 ("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 --- fs/ext4/mballoc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 3fa5de892d89d..98e12326b0d6a 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2414,7 +2414,7 @@ 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;