This is a note to let you know that I've just added the patch titled
ext4: correct grp validation in ext4_mb_good_group
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-correct-grp-validation-in-ext4_mb_good_group.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 29861a7364329bae72ddf758ef85ee3aa3f9ac43
Author: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Date: Tue Aug 1 22:31:55 2023 +0800
ext4: correct grp validation in ext4_mb_good_group
[ 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>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 3a71928846712..2f6ed59d81f02 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -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;
