6.15-stable review patch. If anyone has any objections, please let me know.
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From: Jeongjun Park aha310510@gmail.com
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 --- fs/jbd2/transaction.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1509,7 +1509,7 @@ int jbd2_journal_dirty_metadata(handle_t 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)) { @@ -1528,7 +1528,6 @@ int jbd2_journal_dirty_metadata(handle_t goto out; }
- journal = transaction->t_journal; spin_lock(&jh->b_state_lock);
if (is_handle_aborted(handle)) { @@ -1543,6 +1542,8 @@ int jbd2_journal_dirty_metadata(handle_t goto out_unlock_bh; }
+ journal = transaction->t_journal; + if (jh->b_modified == 0) { /* * This buffer's got modified and becoming part