====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:7/4995 is trying to acquire lock: ffff88807dc76990 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x1a6/0x270 fs/jbd2/transaction.c:177 but task is already holding lock: ffff88807dc74c18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717 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+0x213/0x2e70 fs/ext4/inode.c:2717 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x153/0x1170 fs/fs-writeback.c:1622 writeback_single_inode+0x3d2/0x8e0 fs/fs-writeback.c:1743 write_inode_now+0x17f/0x210 fs/fs-writeback.c:2786 iput_final fs/inode.c:1821 [inline] iput+0x643/0x9c0 fs/inode.c:1860 ext4_xattr_block_set+0x2224/0x2fe0 fs/ext4/xattr.c:2095 ext4_xattr_move_to_block fs/ext4/xattr.c:2613 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2688 [inline] ext4_expand_extra_isize_ea+0xfca/0x1d40 fs/ext4/xattr.c:2776 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:6003 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6046 [inline] __ext4_mark_inode_dirty+0x478/0x760 fs/ext4/inode.c:6124 ext4_evict_inode+0xa67/0x10e0 fs/ext4/inode.c:281 evict+0x4b6/0x8b0 fs/inode.c:705 ext4_orphan_cleanup+0xc32/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5574 [inline] ext4_fill_super+0x6f0c/0x78f0 fs/ext4/super.c:5693 get_tree_bdev+0x3e6/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x247/0xa40 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+0x93c/0x1bc0 fs/ext4/inode.c:5526 notify_change+0xca0/0xf90 fs/attr.c:499 chown_common+0x489/0x640 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+0x2c92/0x7bd0 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+0x7e7/0x2240 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+0xda9/0x2e70 fs/ext4/inode.c:2840 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x153/0x1170 fs/fs-writeback.c:1622 writeback_sb_inodes+0xad5/0x17f0 fs/fs-writeback.c:1913 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984 wb_writeback+0x484/0xd40 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+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 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/u4:7/4995: #0: ffff888143e47138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90003627d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffff88807dc720e0 (&type->s_umount_key#31){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415 #3: ffff88807dc74c18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717 stack backtrace: CPU: 0 PID: 4995 Comm: kworker/u4:7 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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+0x2c92/0x7bd0 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+0x7e7/0x2240 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+0xda9/0x2e70 fs/ext4/inode.c:2840 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x153/0x1170 fs/fs-writeback.c:1622 writeback_sb_inodes+0xad5/0x17f0 fs/fs-writeback.c:1913 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984 wb_writeback+0x484/0xd40 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+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295