watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [kworker/u4:2:34] Modules linked in: irq event stamp: 484353 hardirqs last enabled at (484352): [] restore_regs_and_return_to_kernel+0x0/0x2a hardirqs last disabled at (484353): [] apic_timer_interrupt+0x8e/0xa0 arch/x86/entry/entry_64.S:793 softirqs last enabled at (479462): [] tipc_unregister_callbacks net/tipc/server.c:192 [inline] softirqs last enabled at (479462): [] tipc_close_conn+0xdd/0x200 net/tipc/server.c:200 softirqs last disabled at (479464): [] spin_lock_bh include/linux/spinlock.h:322 [inline] softirqs last disabled at (479464): [] tipc_subscrb_subscrp_delete+0x32/0x330 net/tipc/subscr.c:201 CPU: 0 PID: 34 Comm: kworker/u4:2 Not tainted 4.14.260-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tipc_send tipc_send_work task: ffff8880b56b61c0 task.stack: ffff8880b56b8000 RIP: 0010:__read_once_size include/linux/compiler.h:185 [inline] RIP: 0010:lock_timer_base+0xaa/0x190 kernel/time/timer.c:918 RSP: 0018:ffff8880b56bfae8 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff10 RAX: ffff8880b56b61c0 RBX: 00000000010c0008 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff8880b56bfb58 RDI: ffff8880b0538b18 RBP: ffff8880b0538b18 R08: ffffffff8c070d08 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880b0538b18 R13: ffffed10160a7168 R14: ffff8880b56bfb58 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e428000 CR3: 0000000008e6a000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: del_timer kernel/time/timer.c:1154 [inline] del_timer+0x8b/0xe0 kernel/time/timer.c:1145 tipc_subscrb_subscrp_delete+0x13a/0x330 net/tipc/subscr.c:207 tipc_subscrb_delete net/tipc/subscr.c:238 [inline] tipc_subscrb_release_cb+0x13/0x20 net/tipc/subscr.c:316 tipc_close_conn+0x16a/0x200 net/tipc/server.c:203 tipc_send_to_sock net/tipc/server.c:538 [inline] tipc_send_work+0x41e/0x520 net/tipc/server.c:564 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 00 41 39 5c 24 28 0f 84 99 00 00 00 48 89 74 24 08 e8 4a 40 0d 00 48 8b 74 24 08 48 89 ef e8 2d 00 dc 05 e8 38 40 0d 00 f3 90 31 40 0d 00 48 8b 04 24 41 0f b6 55 00 83 e0 07 83 c0 03 38 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff8723ed1e ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 41 39 5c 24 28 cmp %ebx,0x28(%r12) 7: 0f 84 99 00 00 00 je 0xa6 d: 48 89 74 24 08 mov %rsi,0x8(%rsp) 12: e8 4a 40 0d 00 callq 0xd4061 17: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 1c: 48 89 ef mov %rbp,%rdi 1f: e8 2d 00 dc 05 callq 0x5dc0051 24: e8 38 40 0d 00 callq 0xd4061 29: f3 90 pause * 2b: e8 31 40 0d 00 callq 0xd4061 <-- trapping instruction 30: 48 8b 04 24 mov (%rsp),%rax 34: 41 0f b6 55 00 movzbl 0x0(%r13),%edx 39: 83 e0 07 and $0x7,%eax 3c: 83 c0 03 add $0x3,%eax 3f: 38 .byte 0x38