INFO: task kworker/u4:4:833 blocked for more than 143 seconds. Not tainted 5.15.0-rc6-next-20211020-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:23848 pid: 833 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:4965 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6246 schedule+0xd2/0x260 kernel/sched/core.c:6319 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6378 __mutex_lock_common kernel/locking/mutex.c:672 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:732 wg_netns_pre_exit+0x15/0x190 drivers/net/wireguard/device.c:402 ops_pre_exit_list net/core/net_namespace.c:158 [inline] cleanup_net+0x451/0xb00 net/core/net_namespace.c:581 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 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb835a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 4 locks held by kworker/u4:4/833: #0: ffff8880155a2938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880155a2938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff8880155a2938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff8880155a2938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff8880155a2938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff8880155a2938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc900042cfdb0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 #2: ffffffff8d2e9390 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:555 #3: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x15/0x190 drivers/net/wireguard/device.c:402 1 lock held by systemd-journal/2966: 1 lock held by in:imklog/6235: #0: ffff8880785025f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by kworker/1:17/9460: #0: ffff888021e22d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888021e22d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888021e22d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888021e22d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff888021e22d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888021e22d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc90006387db0 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 #2: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4590 3 locks held by kworker/0:18/17377: 3 locks held by kworker/0:19/17379: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc900059dfdb0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 #2: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 1 lock held by syz-executor.4/17784: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl.isra.0+0x5b6/0x4230 drivers/net/tun.c:3011 1 lock held by syz-executor.4/17791: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x1a7/0xee0 net/core/dev_ioctl.c:586 1 lock held by syz-executor.4/17814: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl.isra.0+0x5b6/0x4230 drivers/net/tun.c:3011 1 lock held by syz-executor.0/17818: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569 1 lock held by syz-executor.2/17819: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc6-next-20211020-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: 2966 Comm: systemd-journal Not tainted 5.15.0-rc6-next-20211020-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data kernel/kcov.c:221 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x15/0x80 kernel/kcov.c:273 Code: 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 40 70 02 00 <48> 89 ce 4c 8b 54 24 08 e8 4e f7 ff ff 84 c0 74 51 48 8b 81 90 15 RSP: 0018:ffffc90001d5fbc8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc90001d5fce0 RCX: ffff88807af70000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003 RBP: ffff8880771c7028 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81cc4938 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000040 R15: 0000000000000040 FS: 00007f24d06b18c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f24cdb9e000 CR3: 000000002181c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:723 [inline] try_to_unlazy+0x157/0x3b0 fs/namei.c:781 complete_walk+0x10d/0x320 fs/namei.c:883 path_lookupat+0x2d1/0x860 fs/namei.c:2456 filename_lookup+0x1c6/0x590 fs/namei.c:2478 user_path_at_empty+0x42/0x60 fs/namei.c:2801 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x127/0x850 fs/open.c:421 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: 0033:0x7f24cf96c9c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffdd0e12f08 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffdd0e15e20 RCX: 00007f24cf96c9c7 RDX: 00007f24d03dda00 RSI: 0000000000000000 RDI: 000055ffcb8a89a3 RBP: 00007ffdd0e12f40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffdd0e15e20 R15: 00007ffdd0e13430 ---------------- Code disassembly (best guess): 0: 00 48 89 add %cl,-0x77(%rax) 3: 4c 38 f0 rex.WR cmp %r14b,%al 6: 4e 89 54 c8 20 mov %r10,0x20(%rax,%r9,8) b: 48 89 10 mov %rdx,(%rax) e: c3 retq f: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 15: 53 push %rbx 16: 41 89 fb mov %edi,%r11d 19: 41 89 f1 mov %esi,%r9d 1c: bf 03 00 00 00 mov $0x3,%edi 21: 65 48 8b 0c 25 40 70 mov %gs:0x27040,%rcx 28: 02 00 * 2a: 48 89 ce mov %rcx,%rsi <-- trapping instruction 2d: 4c 8b 54 24 08 mov 0x8(%rsp),%r10 32: e8 4e f7 ff ff callq 0xfffff785 37: 84 c0 test %al,%al 39: 74 51 je 0x8c 3b: 48 rex.W 3c: 8b .byte 0x8b 3d: 81 .byte 0x81 3e: 90 nop 3f: 15 .byte 0x15