INFO: task kworker/u4:0:3184 blocked for more than 143 seconds. Not tainted 5.15.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:0 state:D stack:24144 pid: 3184 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xc8d/0x1270 kernel/sched/core.c:6287 schedule+0x14b/0x210 kernel/sched/core.c:6366 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425 __mutex_lock_common+0xdff/0x2550 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:743 tc_action_net_exit include/net/act_api.h:155 [inline] gate_exit_net+0x2c/0x100 net/sched/act_gate.c:624 ops_exit_list net/core/net_namespace.c:171 [inline] cleanup_net+0x7ec/0xc50 net/core/net_namespace.c:591 process_one_work+0x853/0x1140 kernel/workqueue.c:2297 worker_thread+0xac1/0x1320 kernel/workqueue.c:2444 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91c180 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/0:3/1286: #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140 #1: ffffc90004bcfd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2272 #2: ffffffff8d95b408 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 1 lock held by in:imklog/6218: #0: ffff888079e78870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:990 3 locks held by kworker/0:13/11988: #0: ffff888025e61d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140 #1: ffffc900049ffd20 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2272 #2: ffffffff8d95b408 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4590 3 locks held by kworker/u4:24/13584: #0: ffff8880111b7138 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140 #1: ffffc9000461fd20 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2272 #2: ffffffff8d95b408 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_dfs_channels_update_work+0xbc/0x660 net/wireless/mlme.c:842 3 locks held by kworker/0:7/31930: #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140 #1: ffffc90018f4fd20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2272 #2: ffffffff8d95b408 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 4 locks held by kworker/u4:0/3184: #0: ffff8881441cb138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140 #1: ffffc90016e77d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2272 #2: ffffffff8d94f7b0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf0/0xc50 net/core/net_namespace.c:553 #3: ffffffff8d95b408 (rtnl_mutex){+.+.}-{3:3}, at: tc_action_net_exit include/net/act_api.h:155 [inline] #3: ffffffff8d95b408 (rtnl_mutex){+.+.}-{3:3}, at: gate_exit_net+0x2c/0x100 net/sched/act_gate.c:624 2 locks held by syz-executor.3/8808: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc1-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+0x1dc/0x2d8 lib/dump_stack.c:106 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc54/0xca0 kernel/hung_task.c:295 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8808 Comm: syz-executor.3 Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_lockdep_current_cpu_online+0xfd/0x130 kernel/rcu/tree.c:1173 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 79 d9 60 00 49 f7 06 01 00 00 00 75 04 31 c0 eb 02 b0 01 65 ff 0d 6b f9 94 7e <74> 08 5b 41 5c 41 5e 41 5f c3 e8 b4 62 93 ff eb f1 48 c7 c7 a0 0b RSP: 0018:ffffc90000dc0b38 EFLAGS: 00000086 RAX: 1ffffffff1924001 RBX: ffffffff8c9203b0 RCX: 0000000080010203 RDX: 0000000000000000 RSI: 0000000000010204 RDI: ffff8880b9d323d8 RBP: ffffc90000dc0bf0 R08: dffffc0000000000 R09: ffffed10173a64a2 R10: ffffed10173a64a2 R11: 0000000000000000 R12: 0000000000000002 R13: 1ffff920001b8190 R14: ffffffff8c920340 R15: dffffc0000000000 FS: 00007fdccd2f0700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0006677f8 CR3: 0000000082e2f000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_sched_held+0x74/0x130 kernel/rcu/update.c:123 trace_lock_release+0x4f/0x150 include/trace/events/lock.h:58 lock_release+0x82/0x810 kernel/locking/lockdep.c:5636 seqcount_lockdep_reader_access+0x111/0x230 include/linux/seqlock.h:102 ktime_get_update_offsets_now+0x45/0x460 kernel/time/timekeeping.c:2297 hrtimer_update_base kernel/time/hrtimer.c:631 [inline] hrtimer_interrupt+0x143/0x1040 kernel/time/hrtimer.c:1793 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:lock_acquire+0x21f/0x4d0 kernel/locking/lockdep.c:5629 Code: 08 4c 89 f7 e8 c2 d1 69 00 f6 84 24 81 00 00 00 02 0f 85 13 02 00 00 41 f7 c4 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 43 c7 44 2f 09 00 00 00 00 43 c7 44 2f 11 RSP: 0018:ffffc90003d5e560 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920007abcbc RCX: ffff88807beec2f0 RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: ffffc90003d5e6b8 R08: dffffc0000000000 R09: fffffbfff1fa2fd1 R10: fffffbfff1fa2fd1 R11: 0000000000000000 R12: 0000000000000246 R13: 1ffff920007abcb4 R14: ffffc90003d5e5e0 R15: dffffc0000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] nf_conntrack_lock net/netfilter/nf_conntrack_core.c:87 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2230 [inline] nf_ct_iterate_cleanup+0xf8/0x3f0 net/netfilter/nf_conntrack_core.c:2275 nf_ct_iterate_cleanup_net+0x172/0x1e0 net/netfilter/nf_conntrack_core.c:2363 masq_device_event+0x9b/0xd0 net/netfilter/nf_nat_masquerade.c:88 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xe7/0x170 kernel/notifier.c:391 __dev_notify_flags+0x306/0x5e0 dev_change_flags+0xe3/0x190 net/core/dev.c:8833 do_setlink+0xe12/0x4300 net/core/rtnetlink.c:2719 rtnl_group_changelink net/core/rtnetlink.c:3242 [inline] __rtnl_newlink net/core/rtnetlink.c:3396 [inline] rtnl_newlink+0x1155/0x1d10 net/core/rtnetlink.c:3506 rtnetlink_rcv_msg+0x934/0xe60 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2504 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x814/0x9f0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0xa29/0xe50 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x5b9/0x910 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmsg+0x36f/0x450 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fdccfd79739 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdccd2f0188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdccfe7df80 RCX: 00007fdccfd79739 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000007 RBP: 00007fdccfdd3cc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdccfe7df80 R13: 00007ffef0d45a9f R14: 00007fdccd2f0300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: f0 48 c1 e8 03 lock shr $0x3,%rax 5: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 79 d9 60 00 callq 0x60d98d 14: 49 f7 06 01 00 00 00 testq $0x1,(%r14) 1b: 75 04 jne 0x21 1d: 31 c0 xor %eax,%eax 1f: eb 02 jmp 0x23 21: b0 01 mov $0x1,%al 23: 65 ff 0d 6b f9 94 7e decl %gs:0x7e94f96b(%rip) # 0x7e94f995 * 2a: 74 08 je 0x34 <-- trapping instruction 2c: 5b pop %rbx 2d: 41 5c pop %r12 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: c3 retq 34: e8 b4 62 93 ff callq 0xff9362ed 39: eb f1 jmp 0x2c 3b: 48 rex.W 3c: c7 .byte 0xc7 3d: c7 (bad) 3e: a0 .byte 0xa0 3f: 0b .byte 0xb