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| author | Luis Henriques (SUSE) <luis.henriques@linux.dev> | 2024-05-15 11:28:57 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2024-06-27 17:26:28 +0300 |
| commit | 907c3fe532253a6ef4eb9c4d67efb71fab58c706 (patch) | |
| tree | 759a2dc96eacad8c28b34d54e8a44b9a6d817169 | |
| parent | b07855348b305c234d9fabb7ab9b50fa9b3a7759 (diff) | |
| download | linux-907c3fe532253a6ef4eb9c4d67efb71fab58c706.tar.xz | |
ext4: fix infinite loop when replaying fast_commit
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@linux.dev>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20240515082857.32730-1-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/extents_status.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 4a00e2f019d9..3a53dbb85e15 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; |