INFO: task syz-executor.5:5907 blocked for more than 143 seconds. Not tainted 6.1.0-next-20221216-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:28712 pid:5907 ppid:5110 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x2544/0x53f0 kernel/sched/core.c:6555 schedule+0xde/0x1b0 kernel/sched/core.c:6631 d_wait_lookup fs/dcache.c:2625 [inline] d_alloc_parallel+0xd85/0x1410 fs/dcache.c:2707 __lookup_slow+0x193/0x460 fs/namei.c:1670 lookup_slow fs/namei.c:1702 [inline] walk_component+0x33f/0x5a0 fs/namei.c:1993 lookup_last fs/namei.c:2450 [inline] path_lookupat+0x1ba/0x840 fs/namei.c:2474 filename_lookup+0x1d2/0x590 fs/namei.c:2503 user_path_at_empty+0x46/0x60 fs/namei.c:2876 user_path_at include/linux/namei.h:57 [inline] ksys_umount fs/namespace.c:1927 [inline] __do_sys_umount fs/namespace.c:1935 [inline] __se_sys_umount fs/namespace.c:1933 [inline] __x64_sys_umount+0xfc/0x190 fs/namespace.c:1933 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f789cc8c0d9 RSP: 002b:00007f789da81168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f789cdac050 RCX: 00007f789cc8c0d9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000200003c0 RBP: 00007f789cce7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe8e15e6ef R14: 00007f789da81300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c791d70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c791a70 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8c7928c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x57/0x2c2 kernel/locking/lockdep.c:6494 2 locks held by getty/4744: #0: ffff88802b3b2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc900015802f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177 1 lock held by syz-executor.3/5108: #0: ffffffff8c79d578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #0: ffffffff8c79d578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x24f/0x780 kernel/rcu/tree_exp.h:946 2 locks held by kworker/1:4/5156: #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x86d/0x1710 kernel/workqueue.c:2260 #1: ffffc90004a4fda8 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1710 kernel/workqueue.c:2264 4 locks held by kworker/u4:6/5172: #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x86d/0x1710 kernel/workqueue.c:2260 #1: ffffc90004af7da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1710 kernel/workqueue.c:2264 #2: ffffffff8e0ace50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9f/0xb10 net/core/net_namespace.c:568 #3: ffffffff8c79d440 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3995 2 locks held by syz-executor.5/5899: 1 lock held by syz-executor.5/5907: #0: ffff888084be0690 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:766 [inline] #0: ffff888084be0690 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow fs/namei.c:1701 [inline] #0: ffff888084be0690 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: walk_component+0x332/0x5a0 fs/namei.c:1993 2 locks held by syz-executor.1/7250: 2 locks held by syz-executor.1/7251: 3 locks held by syz-executor.4/7262: #0: ffffffff8e0ace50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f8/0x6b0 net/core/net_namespace.c:479 #1: ffffffff8e0c0ae8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x92/0x590 net/core/dev.c:11334 #2: ffffffff8c79d578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #2: ffffffff8c79d578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x24f/0x780 kernel/rcu/tree_exp.h:946 1 lock held by syz-executor.0/7279: #0: ffffffff8c79d440 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3995 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.0-next-20221216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x24/0x18a lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x32f/0x3c0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xc75/0xfc0 kernel/hung_task.c:377 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5363 Comm: kworker/u4:9 Not tainted 6.1.0-next-20221216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:write_comp_data+0x7/0x90 kernel/kcov.c:230 Code: 81 e2 00 01 ff 00 75 10 65 48 8b 04 25 00 ac 03 00 48 8b 80 60 15 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 65 8b 05 31 5e 82 7e <49> 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 RSP: 0018:ffffc900054d7a60 EFLAGS: 00000046 RAX: 0000000080000001 RBX: ffffffff91c36788 RCX: ffffffff81707e9c RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffff8880b9929600 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000b R13: 0000000000000001 R14: 0000000100005108 R15: ffffffff91c367a8 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32522000 CR3: 000000000c48e000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: enqueue_timer+0x20c/0x660 kernel/time/timer.c:616 internal_add_timer kernel/time/timer.c:634 [inline] __mod_timer+0x8b5/0xe80 kernel/time/timer.c:1131 add_timer+0x62/0x90 kernel/time/timer.c:1244 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1676 queue_delayed_work_on+0x109/0x120 kernel/workqueue.c:1701 queue_delayed_work include/linux/workqueue.h:518 [inline] toggle_allocation_gate mm/kfence/core.c:806 [inline] toggle_allocation_gate+0x188/0x230 mm/kfence/core.c:791 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308