This is a note to let you know that I've just added the patch titled
ext4: fix infinite loop when replaying fast_commit
to the 6.6-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-fix-infinite-loop-when-replaying-fast_commit.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1eca0845e51616d5db488e0f80d98813a1535b2b
Author: Luis Henriques (SUSE) <luis.henriques@xxxxxxxxx>
Date: Wed May 15 09:28:57 2024 +0100
ext4: fix infinite loop when replaying fast_commit
[ Upstream commit 907c3fe532253a6ef4eb9c4d67efb71fab58c706 ]
When doing fast_commit replay an infinite loop may occur due to an
uninitialized extent_status struct. ext4_ext_determine_insert_hole() does
not detect the replay and calls ext4_es_find_extent_range(), which will
return immediately without initializing the 'es' variable.
Because 'es' contains garbage, an integer overflow may happen causing an
infinite loop in this function, easily reproducible using fstest generic/039.
This commit fixes this issue by unconditionally initializing the structure
in function ext4_es_find_extent_range().
Thanks to Zhang Yi, for figuring out the real problem!
Fixes: 8016e29f4362 ("ext4: fast commit recovery path")
Signed-off-by: Luis Henriques (SUSE) <luis.henriques@xxxxxxxxx>
Reviewed-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
Link: https://patch.msgid.link/20240515082857.32730-1-luis.henriques@xxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index f4b50652f0cce..d9d5cfb9c951a 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -310,6 +310,8 @@ void ext4_es_find_extent_range(struct inode *inode,
ext4_lblk_t lblk, ext4_lblk_t end,
struct extent_status *es)
{
+ es->es_lblk = es->es_len = es->es_pblk = 0;
+
if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
return;
