syzbot

watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.2.131:719]
Modules linked in:
CPU: 0 PID: 719 Comm: syz.2.131 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:375 [inline]
RIP: 0010:__rcu_read_lock+0x29/0x50 kernel/rcu/tree_plugin.h:398
Code: 00 55 48 89 e5 53 65 48 8b 1d 13 c4 aa 7e 48 81 c3 4c 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 05 ff 03 5b 5d c3 89 d9 80 e1 07 80 c1 03 38 c1 7c ef 48
RSP: 0018:ffffc900036ae6a8 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: ffff88811959abcc RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 00000000bc0d2ca1 RDI: ffff88810ad51000
RBP: ffffc900036ae6b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520006d5ce8 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000026 R15: 00000000bc0d2ca1
FS:  00007fca5f5c16c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fca5f5c0ff8 CR3: 0000000122d3b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_read_lock include/linux/rcupdate.h:747 [inline]
 net_generic include/net/netns/generic.h:44 [inline]
 tipc_sk_lookup+0xa1/0x5f0 net/tipc/socket.c:2995
 tipc_sk_rcv+0x3aa/0x2c20 net/tipc/socket.c:2492
 tipc_node_xmit+0x26c/0xd80 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_rcv+0x19f7/0x2c20 net/tipc/socket.c:2501
 tipc_node_xmit+0x26c/0xd80 net/tipc/node.c:1703
 tipc_sk_push_backlog+0x4dd/0x790 net/tipc/socket.c:1316
 tipc_sk_conn_proto_rcv net/tipc/socket.c:1370 [inline]
 tipc_sk_proto_rcv+0xa65/0x1560 net/tipc/socket.c:2158
 tipc_sk_filter_rcv+0x2ac0/0x2cb0 net/tipc/socket.c:2352
 tipc_sk_enqueue net/tipc/socket.c:2445 [inline]
 tipc_sk_rcv+0x794/0x2c20 net/tipc/socket.c:2497
 tipc_node_xmit+0x26c/0xd80 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:1090 [inline]
 __release_sock+0x17c/0x3f0 net/core/sock.c:2737
 release_sock net/core/sock.c:3290 [inline]
 sock_setsockopt+0x1d7a/0x2490 net/core/sock.c:1381
 __sys_setsockopt+0x261/0x470 net/socket.c:2198
 __do_sys_setsockopt net/socket.c:2213 [inline]
 __se_sys_setsockopt net/socket.c:2210 [inline]
 __x64_sys_setsockopt+0xbf/0xd0 net/socket.c:2210
 x64_sys_call+0x982/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:55
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fca5f77df79
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:00007fca5f5c1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fca5f9f9090 RCX: 00007fca5f77df79
RDX: 0000000000000021 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 00007fca5f8146e0 R08: 0000000000000004 R09: 0000000000000000
R10: 0000200000000540 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fca5f9f9128 R14: 00007fca5f9f9090 R15: 00007ffe2210ab08
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 718 Comm: syz.2.131 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x527/0x9c0 kernel/locking/qspinlock.c:508
Code: 00 41 c6 45 00 00 48 8b 44 24 10 42 0f b6 04 38 84 c0 0f 85 1c 01 00 00 48 8b 44 24 08 c6 00 01 41 bd 00 80 ff ff eb 07 f3 90 <41> ff c5 74 47 43 0f b6 04 3e 84 c0 75 2b 80 3b 00 75 eb 48 89 df
RSP: 0018:ffffc90003447760 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffff88810f94b288 RCX: ffffffff815008c9
RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffff88810f94b288
RBP: ffffc90003447850 R08: ffff88810f94b288 R09: 1ffff11021f29651
R10: dffffc0000000000 R11: ffffed1021f29652 R12: 1ffff1103ee20001
R13: 00000000ffffbea7 R14: 1ffff11021f29651 R15: dffffc0000000000
FS:  00007fca5f5e26c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 0000000122d3b000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:188 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0xe4/0xf0 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:369 [inline]
 lock_sock_nested+0x95/0x2a0 net/core/sock.c:3278
 lock_sock include/net/sock.h:1743 [inline]
 tipc_sendstream+0x47/0x70 net/tipc/socket.c:1549
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2435
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2489
 __sys_sendmsg net/socket.c:2518 [inline]
 __do_sys_sendmsg net/socket.c:2527 [inline]
 __se_sys_sendmsg net/socket.c:2525 [inline]
 __x64_sys_sendmsg+0x206/0x2f0 net/socket.c:2525
 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fca5f77df79
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:00007fca5f5e2028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fca5f9f8fa0 RCX: 00007fca5f77df79
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000004
RBP: 00007fca5f8146e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fca5f9f9038 R14: 00007fca5f9f8fa0 R15: 00007ffe2210ab08
 </TASK>