====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:5/4466 is trying to acquire lock: ffff88814dc36990 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x1a6/0x270 fs/jbd2/transaction.c:177 but task is already holding lock: ffff88814dc34b98 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x20f/0x2f40 fs/ext4/inode.c:2715 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sbi->s_writepages_rwsem){.+.+}-{0:0}: percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x20f/0x2f40 fs/ext4/inode.c:2715 do_writepages+0x3ba/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1622 writeback_single_inode+0x3cb/0x8e0 fs/fs-writeback.c:1743 write_inode_now+0x17f/0x210 fs/fs-writeback.c:2780 iput_final fs/inode.c:1821 [inline] iput+0x613/0x980 fs/inode.c:1860 ext4_xattr_block_set+0x273b/0x32b0 fs/ext4/xattr.c:2145 ext4_xattr_move_to_block fs/ext4/xattr.c:2610 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2685 [inline] ext4_expand_extra_isize_ea+0x120b/0x1dc0 fs/ext4/xattr.c:2773 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5984 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6027 [inline] __ext4_mark_inode_dirty+0x47f/0x770 fs/ext4/inode.c:6105 ext4_evict_inode+0xa7f/0x1110 fs/ext4/inode.c:279 evict+0x4c9/0x8d0 fs/inode.c:705 ext4_orphan_cleanup+0xbeb/0x1420 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5556 [inline] ext4_fill_super+0x7829/0x7dc0 fs/ext4/super.c:5687 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&ei->xattr_sem){++++}-{3:3}: down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 ext4_setattr+0x92a/0x19f0 fs/ext4/inode.c:5519 notify_change+0xc74/0xf40 fs/attr.c:499 chown_common+0x4a0/0x660 fs/open.c:736 do_fchownat+0x147/0x240 fs/open.c:767 __do_sys_chown fs/open.c:787 [inline] __se_sys_chown fs/open.c:785 [inline] __x64_sys_chown+0x7e/0x90 fs/open.c:785 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (jbd2_handle){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 wait_transaction_locked+0x1bf/0x270 fs/jbd2/transaction.c:177 add_transaction_credits fs/jbd2/transaction.c:241 [inline] start_this_handle+0x7ec/0x2230 fs/jbd2/transaction.c:422 jbd2__journal_start+0x2b7/0x5a0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x187/0x3d0 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_writepages+0xe78/0x2f40 fs/ext4/inode.c:2838 do_writepages+0x3ba/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1622 writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984 wb_writeback+0x494/0xd50 fs/fs-writeback.c:2089 wb_check_old_data_flush fs/fs-writeback.c:2189 [inline] wb_do_writeback fs/fs-writeback.c:2242 [inline] wb_workfn+0xb68/0xee0 fs/fs-writeback.c:2270 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 other info that might help us debug this: Chain exists of: jbd2_handle --> &ei->xattr_sem --> &sbi->s_writepages_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(jbd2_handle); *** DEADLOCK *** 4 locks held by kworker/u4:5/4466: #0: ffff88801c668138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc900035c7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffff88814dc320e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415 #3: ffff88814dc34b98 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x20f/0x2f40 fs/ext4/inode.c:2715 stack backtrace: CPU: 1 PID: 4466 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 wait_transaction_locked+0x1bf/0x270 fs/jbd2/transaction.c:177 add_transaction_credits fs/jbd2/transaction.c:241 [inline] start_this_handle+0x7ec/0x2230 fs/jbd2/transaction.c:422 jbd2__journal_start+0x2b7/0x5a0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x187/0x3d0 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_writepages+0xe78/0x2f40 fs/ext4/inode.c:2838 do_writepages+0x3ba/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1622 writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984 wb_writeback+0x494/0xd50 fs/fs-writeback.c:2089 wb_check_old_data_flush fs/fs-writeback.c:2189 [inline] wb_do_writeback fs/fs-writeback.c:2242 [inline] wb_workfn+0xb68/0xee0 fs/fs-writeback.c:2270 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295