5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Luis Henriques (SUSE) <luis.henriques@xxxxxxxxx>
[ 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>
---
fs/ext4/extents_status.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index cccbdfd49a86b..ee52dd6afe543 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -312,6 +312,8 @@ 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;
--
2.43.0
