INFO: task kworker/u4:7:2453 blocked for more than 143 seconds. Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:7 state:D stack:21904 pid:2453 tgid:2453 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0x1961/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a3/0xd60 kernel/locking/mutex.c:747 jfs_commit_inode+0x246/0x580 fs/jfs/inode.c:102 jfs_write_inode+0x143/0x210 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1473 [inline] __writeback_single_inode+0x69b/0xfc0 fs/fs-writeback.c:1690 writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1987 wb_writeback+0x461/0xc70 fs/fs-writeback.c:2094 wb_check_background_flush fs/fs-writeback.c:2164 [inline] wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0xc33/0xfb0 fs/fs-writeback.c:2279 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2703 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2784 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d92cf60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8d92cf60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8d92cf60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 4 locks held by kworker/u4:7/2453: #0: ffff88801aa6e538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline] #0: ffff88801aa6e538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2703 #1: ffffc90009d87d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline] #1: ffffc90009d87d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2703 #2: ffff88802727a0e0 (&type->s_umount_key#54){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:610 #3: ffff888072963008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x246/0x580 fs/jfs/inode.c:102 2 locks held by getty/4818: #0: ffff8880262170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 4 locks held by syz-executor.0/5478: 1 lock held by syz-executor.0/6216: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x310 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5782 Comm: syz-executor.0 Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:visit_lock_entry kernel/locking/lockdep.c:1520 [inline] RIP: 0010:__bfs kernel/locking/lockdep.c:1800 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1844 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2804 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3138 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3253 [inline] RIP: 0010:validate_chain+0x2039/0x5ab0 kernel/locking/lockdep.c:3869 Code: 41 b4 01 eb 0c 4d 8b 3f 4d 39 f7 0f 84 e7 00 00 00 49 8d 5f 30 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 bd 8f 7c 00 4c 89 2b 41 f6 c4 01 74 7f 8b 1d 52 RSP: 0018:ffffc90007026a80 EFLAGS: 00000046 RAX: 1ffffffff23df2ab RBX: ffffffff91ef9558 RCX: dffffc0000000000 RDX: ffff88806284c700 RSI: 0000000000000008 RDI: ffffffff90ab5db0 RBP: ffffc90007026d80 R08: ffffffff90dd7367 R09: 1ffffffff21bae6c R10: dffffc0000000000 R11: fffffbfff21bae6d R12: 0000000000000000 R13: ffffffff91e8f6b8 R14: ffffffff90ab5d80 R15: ffffffff91ef9528 FS: 0000555555673480(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555555684978 CR3: 0000000020524000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 update_cfs_rq_load_avg kernel/sched/fair.c:4529 [inline] update_load_avg+0x1fc/0x1810 kernel/sched/fair.c:4688 put_prev_entity+0x6f/0x210 kernel/sched/fair.c:5441 pick_next_task_fair+0x3da/0xdd0 kernel/sched/fair.c:8395 __pick_next_task kernel/sched/core.c:5997 [inline] pick_next_task kernel/sched/core.c:6072 [inline] __schedule+0x7ce/0x4ab0 kernel/sched/core.c:6652 preempt_schedule_common+0x83/0xc0 kernel/sched/core.c:6865 preempt_schedule+0xdd/0xf0 kernel/sched/core.c:6889 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 unwind_next_frame+0x211e/0x29e0 arch/x86/kernel/unwind_orc.c:672 __unwind_start+0x641/0x7a0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xfd/0x1a0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x117/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0xb3/0x1a0 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x730 security/tomoyo/file.c:822 tomoyo_path_unlink+0xd0/0x110 security/tomoyo/tomoyo.c:161 security_path_unlink+0xdb/0x130 security/security.c:1767 do_unlinkat+0x3e6/0x830 fs/namei.c:4379 __do_sys_unlink fs/namei.c:4430 [inline] __se_sys_unlink fs/namei.c:4428 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4428 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f9203a7c297 Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcaa3f2a48 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9203a7c297 RDX: 00007ffcaa3f2a70 RSI: 00007ffcaa3f2b00 RDI: 00007ffcaa3f2b00 RBP: 00007ffcaa3f2b00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffcaa3f3bc0 R13: 00007f9203ac73b9 R14: 0000000000039ae5 R15: 0000000000000002