syzbot

watchdog: BUG: soft lockup - CPU#1 stuck for 143s! [syz.2.17:374]
Modules linked in:
CPU: 1 PID: 374 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x105/0x150 arch/x86/kernel/kvm.c:1064
Code: 07 33 04 f4 eb 87 fa 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 3f 0f b6 07 40 38 f0 75 10 66 90 0f 00 2d 5d 07 33 04 fb f4 <e9> 5e ff ff ff fb e9 58 ff ff ff e8 1b aa c4 03 89 f9 80 e1 07 38
RSP: 0018:ffffc900017178a0 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffff88812aaccf98 RCX: ffffffff8500b8a2
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff88812aaccf98
RBP: ffffc90001717930 R08: ffff88812aaccf98 R09: 1ffff110255599f3
R10: dffffc0000000000 R11: ffffed10255599f4 R12: 1ffff1103ede0001
R13: ffff8881f6f38cd4 R14: dffffc0000000000 R15: 1ffff920002e2f14
FS:  000055558f335500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0ff13e9e80 CR3: 000000012a62d000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x690/0xc40 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline]
 _raw_spin_lock_bh+0xe4/0xf0 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 lock_sock_nested+0x90/0x2a0 net/core/sock.c:3515
 lock_sock include/net/sock.h:1818 [inline]
 tipc_release+0xb2/0x1670 net/tipc/socket.c:639
 __sock_release net/socket.c:652 [inline]
 sock_close+0xf1/0x290 net/socket.c:1389
 __fput+0x1fc/0x8f0 fs/file_table.c:320
 ____fput+0x15/0x20 fs/file_table.c:348
 task_work_run+0x1e1/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0ff139c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdd9fbb658 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f0ff1617da0 RCX: 00007f0ff139c799
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f0ff1617da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f0ff1617cb0 R11: 0000000000000246 R12: 0000000000034e69
R13: 00007f0ff161609c R14: 0000000000034b8e R15: 00007f0ff1616090
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:216
Code: b0 00 91 7e 65 8b 15 b1 00 91 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 6c 0b 00 00 00 74 2c 8b 91 48 0b 00 00 <83> fa 02 75 21 48 8b 91 50 0b 00 00 48 8b 32 48 8d 7e 01 8b 89 4c
RSP: 0018:ffffc900016c6870 EFLAGS: 00000246
RAX: ffffffff84d95b40 RBX: ffff88812aaccf80 RCX: ffff888113f90000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 000000007ffffffe
RBP: ffffc900016c6870 R08: ffff88812aaccf83 R09: 1ffff110255599f0
R10: dffffc0000000000 R11: ffffed10255599f1 R12: ffff88812aaccf00
R13: 00000000000003f0 R14: 0000000000000004 R15: ffff88811394d0de
FS:  00007f0ff11ff6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003000 CR3: 000000012a62d000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:200 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:791 [inline]
 tipc_sk_lookup+0x530/0x620 net/tipc/socket.c:3003
 tipc_sk_rcv+0x416/0x2c10 net/tipc/socket.c:2492
 tipc_node_xmit+0x26c/0xd90 net/tipc/node.c:1703
 tipc_node_xmit_skb+0xf7/0x150 net/tipc/node.c:1768
 tipc_sk_rcv+0x1d63/0x2c10 net/tipc/socket.c:2522
 tipc_node_xmit+0x26c/0xd90 net/tipc/node.c:1703
 tipc_sk_push_backlog net/tipc/socket.c:1316 [inline]
 tipc_sk_filter_connect net/tipc/socket.c:2255 [inline]
 tipc_sk_filter_rcv+0x158e/0x2cf0 net/tipc/socket.c:2364
 tipc_sk_enqueue net/tipc/socket.c:2445 [inline]
 tipc_sk_rcv+0x7ed/0x2c10 net/tipc/socket.c:2497
 tipc_node_xmit+0x26c/0xd90 net/tipc/node.c:1703
 tipc_node_xmit_skb net/tipc/node.c:1768 [inline]
 tipc_node_distr_xmit+0x2a3/0x3b0 net/tipc/node.c:1783
 tipc_sk_backlog_rcv+0x17d/0x210 net/tipc/socket.c:2412
 sk_backlog_rcv include/net/sock.h:1150 [inline]
 __release_sock+0x154/0x380 net/core/sock.c:2951
 release_sock+0x60/0x1c0 net/core/sock.c:3527
 tipc_release+0xd4a/0x1670 net/tipc/socket.c:652
 __sock_release net/socket.c:652 [inline]
 sock_close+0xf1/0x290 net/socket.c:1389
 __fput+0x1fc/0x8f0 fs/file_table.c:320
 ____fput+0x15/0x20 fs/file_table.c:348
 task_work_run+0x1e1/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0ff139c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0ff11ff028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 00000000000203a0 RBX: 00007f0ff1615fa0 RCX: 00007f0ff139c799
RDX: 0000000000000000 RSI: 00002000000003c0 RDI: 0000000000000003
RBP: 00007f0ff1432bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0ff1616038 R14: 00007f0ff1615fa0 R15: 00007ffdd9fbb4f8
 </TASK>