6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
[ 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@xxxxxxxxxxxxxxx>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230801143204.2284343-2-shikemeng@xxxxxxxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 21b903fe546e8..b00b7adf1461d 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2553,7 +2553,7 @@ static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
BUG_ON(cr < CR_POWER2_ALIGNED || cr >= EXT4_MB_NUM_CRS);
- if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp) || !grp))
+ if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
return false;
free = grp->bb_free;
--
2.40.1
