diff options
| author | Jeongjun Park <aha310510@gmail.com> | 2025-05-14 22:08:55 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-27 11:11:16 +0100 |
| commit | f78b38af3540b4875147b7b884ee11a27b3dbf4c (patch) | |
| tree | c53ad05355c57d71352bf704927f5b3b6f2ebaeb | |
| parent | d35e6c3616b6fc6dcc06c71eaa88ffd6ced408b4 (diff) | |
jbd2: fix data-race and null-ptr-deref in jbd2_journal_dirty_metadata()
commit af98b0157adf6504fade79b3e6cb260c4ff68e37 upstream.
Since handle->h_transaction may be a NULL pointer, so we should change it
to call is_handle_aborted(handle) first before dereferencing it.
And the following data-race was reported in my fuzzer:
==================================================================
BUG: KCSAN: data-race in jbd2_journal_dirty_metadata / jbd2_journal_dirty_metadata
write to 0xffff888011024104 of 4 bytes by task 10881 on cpu 1:
jbd2_journal_dirty_metadata+0x2a5/0x770 fs/jbd2/transaction.c:1556
__ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
__ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
....
read to 0xffff888011024104 of 4 bytes by task 10880 on cpu 0:
jbd2_journal_dirty_metadata+0xf2/0x770 fs/jbd2/transaction.c:1512
__ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
__ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
....
value changed: 0x00000000 -> 0x00000001
==================================================================
This issue is caused by missing data-race annotation for jh->b_modified.
Therefore, the missing annotation needs to be added.
Reported-by: syzbot+de24c3fe3c4091051710@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=de24c3fe3c4091051710
Fixes: 6e06ae88edae ("jbd2: speedup jbd2_journal_dirty_metadata()")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250514130855.99010-1-aha310510@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/jbd2/transaction.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 66513c18ca294..f440110df93a9 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1513,7 +1513,7 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) jh->b_next_transaction == transaction); spin_unlock(&jh->b_state_lock); } - if (jh->b_modified == 1) { + if (data_race(jh->b_modified == 1)) { /* If it's in our transaction it must be in BJ_Metadata list. */ if (data_race(jh->b_transaction == transaction && jh->b_jlist != BJ_Metadata)) { @@ -1532,7 +1532,6 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) goto out; } - journal = transaction->t_journal; spin_lock(&jh->b_state_lock); if (is_handle_aborted(handle)) { @@ -1547,6 +1546,8 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) goto out_unlock_bh; } + journal = transaction->t_journal; + if (jh->b_modified == 0) { /* * This buffer's got modified and becoming part |