INFO: task kworker/u4:1:10 blocked for more than 186 seconds. Not tainted 5.15.0-rc4-next-20211008-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:1 state:D stack:24440 pid: 10 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:4953 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6234 schedule+0xd2/0x260 kernel/sched/core.c:6307 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6366 __mutex_lock_common kernel/locking/mutex.c:672 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:732 rcu_barrier+0x44/0x440 kernel/rcu/tree.c:3996 wg_destruct+0x274/0x430 drivers/net/wireguard/device.c:240 netdev_run_todo+0x6b4/0xa80 net/core/dev.c:10600 default_device_exit_batch+0x2ff/0x3c0 net/core/dev.c:11581 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task syz-executor.3:26071 can't die for more than 186 seconds. task:syz-executor.3 state:R running task stack:24784 pid:26071 ppid: 23252 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4953 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6234 schedule+0xd2/0x260 kernel/sched/core.c:6307 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x174/0x270 kernel/sched/completion.c:138 rcu_barrier+0x2db/0x440 kernel/rcu/tree.c:4061 netdev_run_todo+0x2b2/0xa80 net/core/dev.c:10572 rtnl_unlock net/core/rtnetlink.c:112 [inline] rtnetlink_rcv_msg+0x420/0xb80 net/core/rtnetlink.c:5573 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fdaa858e8d9 RSP: 002b:00007fdaa5aa2188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdaa86931a0 RCX: 00007fdaa858e8d9 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000006 RBP: 00007fdaa85e8cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd7b34507f R14: 00007fdaa5aa2300 R15: 0000000000022000 Showing all locks held in the system: 5 locks held by kworker/u4:1/10: #0: ffff8881407b3138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881407b3138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff8881407b3138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff8881407b3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff8881407b3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff8881407b3138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc90000cf7db0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 #2: ffffffff8d2e1d90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:555 #3: ffff888087e152d0 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x14b/0x430 drivers/net/wireguard/device.c:229 #4: ffffffff8bb8a630 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x44/0x440 kernel/rcu/tree.c:3996 1 lock held by khungtaskd/27: #0: ffffffff8bb813a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by kswapd0/97: 1 lock held by in:imklog/6245: #0: ffff88807f416af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by agetty/6476: #0: ffff88801cad5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc90002a4c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 2 locks held by systemd-udevd/26476: 1 lock held by syz-executor.4/26491: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc4-next-20211008-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.15.0-rc4-next-20211008-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:debug_object_init_on_stack+0x0/0x20 lib/debugobjects.c:632 Code: 44 24 18 e9 9f f5 ff ff 66 90 8b 05 02 17 b5 09 85 c0 75 01 c3 31 d2 e9 de f2 ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <8b> 05 e2 16 b5 09 85 c0 75 01 c3 ba 01 00 00 00 e9 bb f2 ff ff 66 RSP: 0018:ffffc90000cd7b60 EFLAGS: 00000216 RAX: ffff888010e6d700 RBX: 1ffff9200019af6d RCX: 0000000000000000 RDX: ffff888010e6d700 RSI: ffffffff89adec80 RDI: ffffc90000cd7b88 RBP: 000000010000f265 R08: 0000000000000000 R09: 0000000000000003 R10: ffffffff894e3b7f R11: 0000000000000000 R12: ffffc90000cd7b88 R13: ffffffff8b80f180 R14: ffff888010daee00 R15: ffff888010c69800 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020010000 CR3: 000000000b88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: init_timer_on_stack_key kernel/time/timer.c:752 [inline] schedule_timeout+0xf2/0x2a0 kernel/time/timer.c:1879 toggle_allocation_gate mm/kfence/core.c:738 [inline] toggle_allocation_gate+0x305/0x390 mm/kfence/core.c:723 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 44 24 18 rex.R and $0x18,%al 3: e9 9f f5 ff ff jmpq 0xfffff5a7 8: 66 90 xchg %ax,%ax a: 8b 05 02 17 b5 09 mov 0x9b51702(%rip),%eax # 0x9b51712 10: 85 c0 test %eax,%eax 12: 75 01 jne 0x15 14: c3 retq 15: 31 d2 xor %edx,%edx 17: e9 de f2 ff ff jmpq 0xfffff2fa 1c: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 23: 00 00 00 00 27: 0f 1f 00 nopl (%rax) * 2a: 8b 05 e2 16 b5 09 mov 0x9b516e2(%rip),%eax # 0x9b51712 <-- trapping instruction 30: 85 c0 test %eax,%eax 32: 75 01 jne 0x35 34: c3 retq 35: ba 01 00 00 00 mov $0x1,%edx 3a: e9 bb f2 ff ff jmpq 0xfffff2fa 3f: 66 data16