====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ kworker/u8:4/1172 is trying to acquire lock: ffff0000d3d90938 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x170/0x220 fs/jbd2/transaction.c:151 but task is already holding lock: ffff0000d3d92c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff0000d3d92c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] ffff0000d3d92c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x16c/0x2d8 fs/ext4/inode.c:3041 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_internal+0x5c/0x294 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] ext4_writepages+0x16c/0x2d8 fs/ext4/inode.c:3041 do_writepages+0x270/0x468 mm/page-writeback.c:2571 __writeback_single_inode+0x144/0x1808 fs/fs-writeback.c:1764 writeback_single_inode+0x3b8/0xaa0 fs/fs-writeback.c:1883 write_inode_now+0x170/0x208 fs/fs-writeback.c:2974 iput_final fs/inode.c:1950 [inline] iput+0x6bc/0xb90 fs/inode.c:2009 ext4_xattr_block_set+0x12dc/0x2188 fs/ext4/xattr.c:2206 ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline] ext4_expand_extra_isize_ea+0xb18/0x13a0 fs/ext4/xattr.c:2834 __ext4_expand_extra_isize+0x29c/0x370 fs/ext4/inode.c:6434 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline] __ext4_mark_inode_dirty+0x3a4/0x810 fs/ext4/inode.c:6555 ext4_evict_inode+0x7a0/0xfc4 fs/ext4/inode.c:267 evict+0x4b8/0x740 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput+0x858/0xb90 fs/inode.c:2009 ext4_process_orphan+0x240/0x2b4 fs/ext4/orphan.c:358 ext4_orphan_cleanup+0x7b8/0xd30 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5701 [inline] ext4_fill_super+0x45a4/0x4d60 fs/ext4/super.c:5824 get_tree_bdev_flags+0x380/0x434 fs/super.c:1694 get_tree_bdev+0x2c/0x3c fs/super.c:1717 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5856 vfs_get_tree+0x90/0x28c fs/super.c:1754 fc_mount+0x24/0xac fs/namespace.c:1193 do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x2a4/0x540 fs/namespace.c:3834 path_mount+0x5d0/0xa68 fs/namespace.c:4154 do_mount+0xe8/0x148 fs/namespace.c:4167 __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount fs/namespace.c:4360 [inline] __arm64_sys_mount+0x334/0x380 fs/namespace.c:4360 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 -> #1 (&ei->xattr_sem){++++}-{4:4}: down_write+0x50/0xc0 kernel/locking/rwsem.c:1625 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_xattr_set_handle+0x138/0xe00 fs/ext4/xattr.c:2374 ext4_initxattrs+0xa4/0x118 fs/ext4/xattr_security.c:44 security_inode_init_security+0x24c/0x378 security/security.c:1370 ext4_init_security+0x44/0x58 fs/ext4/xattr_security.c:58 __ext4_new_inode+0x28dc/0x3390 fs/ext4/ialloc.c:1330 ext4_create+0x1e8/0x3f4 fs/ext4/namei.c:2827 lookup_open fs/namei.c:4511 [inline] open_last_lookups fs/namei.c:4611 [inline] path_openat+0x1244/0x2a6c fs/namei.c:4855 do_file_open+0x1c4/0x2e4 fs/namei.c:4887 do_sys_openat2+0x114/0x1e8 fs/open.c:1364 do_sys_open+0xac/0xdc fs/open.c:1370 __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __arm64_sys_openat+0x9c/0xb8 fs/open.c:1381 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 -> #0 (jbd2_handle){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1780/0x2f44 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x368 kernel/locking/lockdep.c:5868 wait_transaction_locked+0x178/0x220 fs/jbd2/transaction.c:151 add_transaction_credits fs/jbd2/transaction.c:-1 [inline] start_this_handle+0x5b0/0x1c10 fs/jbd2/transaction.c:403 jbd2__journal_start+0x260/0x520 fs/jbd2/transaction.c:502 __ext4_journal_start_sb+0x228/0x948 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xb18/0x3ac8 fs/ext4/inode.c:2930 ext4_writepages+0x194/0x2d8 fs/ext4/inode.c:3042 do_writepages+0x270/0x468 mm/page-writeback.c:2571 __writeback_single_inode+0x144/0x1808 fs/fs-writeback.c:1764 writeback_sb_inodes+0x79c/0x1744 fs/fs-writeback.c:2056 __writeback_inodes_wb+0xec/0x210 fs/fs-writeback.c:2132 wb_writeback+0x3e8/0x10e0 fs/fs-writeback.c:2243 wb_check_old_data_flush fs/fs-writeback.c:2347 [inline] wb_do_writeback fs/fs-writeback.c:2400 [inline] wb_workfn+0x9ac/0xcb4 fs/fs-writeback.c:2428 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0x79c/0x1098 kernel/workqueue.c:3397 worker_thread+0x754/0xba0 kernel/workqueue.c:3478 kthread+0x2f8/0x3c8 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:842 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 ---- ---- rlock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(jbd2_handle); *** DEADLOCK *** 4 locks held by kworker/u8:4/1172: #0: ffff0000c1f19140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff0000c1f19140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x748/0x1098 kernel/workqueue.c:3397 #1: ffff8000948d7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #1: ffff8000948d7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x750/0x1098 kernel/workqueue.c:3397 #2: ffff0000d3d940d8 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x24/0xdc fs/super.c:565 #3: ffff0000d3d92c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff0000d3d92c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] #3: ffff0000d3d92c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x16c/0x2d8 fs/ext4/inode.c:3041 stack backtrace: CPU: 0 UID: 0 PID: 1172 Comm: kworker/u8:4 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: writeback wb_workfn (flush-259:0) Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x328/0x330 kernel/locking/lockdep.c:2043 check_noncircular+0x158/0x174 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1780/0x2f44 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x368 kernel/locking/lockdep.c:5868 wait_transaction_locked+0x178/0x220 fs/jbd2/transaction.c:151 add_transaction_credits fs/jbd2/transaction.c:-1 [inline] start_this_handle+0x5b0/0x1c10 fs/jbd2/transaction.c:403 jbd2__journal_start+0x260/0x520 fs/jbd2/transaction.c:502 __ext4_journal_start_sb+0x228/0x948 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xb18/0x3ac8 fs/ext4/inode.c:2930 ext4_writepages+0x194/0x2d8 fs/ext4/inode.c:3042 do_writepages+0x270/0x468 mm/page-writeback.c:2571 __writeback_single_inode+0x144/0x1808 fs/fs-writeback.c:1764 writeback_sb_inodes+0x79c/0x1744 fs/fs-writeback.c:2056 __writeback_inodes_wb+0xec/0x210 fs/fs-writeback.c:2132 wb_writeback+0x3e8/0x10e0 fs/fs-writeback.c:2243 wb_check_old_data_flush fs/fs-writeback.c:2347 [inline] wb_do_writeback fs/fs-writeback.c:2400 [inline] wb_workfn+0x9ac/0xcb4 fs/fs-writeback.c:2428 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0x79c/0x1098 kernel/workqueue.c:3397 worker_thread+0x754/0xba0 kernel/workqueue.c:3478 kthread+0x2f8/0x3c8 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:842