From: Jeongjun Park <aha310510@gmail.com> mainline inclusion from mainline-v6.16-rc1 commit af98b0157adf6504fade79b3e6cb260c4ff68e37 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICLHG1 CVE: CVE-2025-38337 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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 Conflicts: fs/jbd2/transaction.c [464170647b56 not applied and KCSAN not supported] Signed-off-by: Yongjian Sun <sunyongjian1@huawei.com> --- fs/jbd2/transaction.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 0797568c5899..ba7ec279c715 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1461,7 +1461,6 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) goto out; } - journal = transaction->t_journal; jbd_lock_bh_state(bh); if (is_handle_aborted(handle)) { @@ -1476,6 +1475,8 @@ 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 -- 2.39.2