BUG: soft lockup in tcp_tasklet_func

Status: auto-obsoleted due to no activity on 2025/09/26 12:22
Reported-by: syzbot+92fe42571128d2d3dfca@syzkaller.appspotmail.com
First crash: 414d, last: 414d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: soft lockup in tcp_tasklet_func 1 1 777d 777d 0/2 auto-obsoleted due to no activity on 2024/09/27 22:34
android-6-1 BUG: soft lockup in tcp_tasklet_func (2) 1 1 296d 296d 0/2 auto-obsoleted due to no activity on 2026/01/22 11:08
linux-5.15 INFO: rcu detected stall in tcp_tasklet_func 1 1 19d 19d 0/3 upstream: reported on 2026/07/27 23:06

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 144s! [syz.0.3622:13358]
Modules linked in:
CPU: 0 PID: 13358 Comm: syz.0.3622 Not tainted 6.1.141-syzkaller-00033-g36d69f6a49eb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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+0xf2/0x140 arch/x86/kernel/kvm.c:1064
Code: ae 13 04 f4 eb 9a 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 90 ae 13 04 fb f4 <e9> 71 ff ff ff fb e9 6b ff ff ff e8 1e 0f b5 03 89 f9 80 e1 07 38
RSP: 0018:ffffc90000007b60 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffff888120c39498 RCX: ffffffff84f06582
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff888120c39498
RBP: ffffc90000007bf0 R08: dffffc0000000000 R09: ffffed1024187294
R10: ffffed1024187294 R11: 1ffff11024187293 R12: 1ffff1103ee00001
R13: ffff8881f7038c94 R14: dffffc0000000000 R15: 1ffff92000000f6c
FS:  00007fa73d0d86c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7e97055f21 CR3: 0000000128531000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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 include/linux/spinlock_api_smp.h:134 [inline]
 _raw_spin_lock+0xd8/0xe0 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 tcp_tsq_handler+0x22/0x150 net/ipv4/tcp_output.c:1032
 tcp_tasklet_func+0x339/0x3c0 net/ipv4/tcp_output.c:1066
 tasklet_action_common+0x22e/0x630 kernel/softirq.c:878
 tasklet_action+0x4c/0x60 kernel/softirq.c:903
 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
 __do_softirq kernel/softirq.c:680 [inline]
 invoke_softirq kernel/softirq.c:497 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741
 common_interrupt+0xbe/0xe0 arch/x86/kernel/irq.c:242
 </IRQ>
 <TASK>
 asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:682
RIP: 0010:csd_lock_wait kernel/smp.c:453 [inline]
RIP: 0010:smp_call_function_many_cond+0x872/0x960 kernel/smp.c:998
Code: 41 8b 1f 89 de 83 e6 01 31 ff e8 39 66 09 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 0a e8 05 62 09 00 e9 38 ff ff ff f3 90 <41> 0f b6 44 1d 00 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 1a ff ff
RSP: 0018:ffffc90001d57660 EFLAGS: 00000283
RAX: ffffffff8166953e RBX: dffffc0000000000 RCX: 0000000000080000
RDX: ffffc900069ee000 RSI: 0000000000002129 RDI: 000000000000212a
RBP: ffffc90001d57798 R08: dffffc0000000000 R09: ffffed103ee07213
R10: 0000000000000000 R11: ffffffff81341b30 R12: 1ffff1103ee07210
R13: 1ffff1103ee2789d R14: 0000000000000001 R15: ffff8881f713c4e8
 on_each_cpu_cond_mask+0x43/0x80 kernel/smp.c:1166
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1574 [inline]
 text_poke_bp_batch+0x505/0x580 arch/x86/kernel/alternative.c:-1
 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline]
 text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1972
 arch_jump_label_transform_apply+0x15/0x30 arch/x86/kernel/jump_label.c:146
 __jump_label_update+0x37c/0x3a0 kernel/jump_label.c:451
 jump_label_update+0x39b/0x450 kernel/jump_label.c:797
 static_key_enable_cpuslocked+0x126/0x240 kernel/jump_label.c:173
 static_key_enable+0x1a/0x30 kernel/jump_label.c:186
 tracepoint_add_func+0x876/0x900 kernel/tracepoint.c:361
 tracepoint_probe_register_prio_may_exist+0x5b/0x90 kernel/tracepoint.c:482
 tracepoint_probe_register_may_exist include/linux/tracepoint.h:52 [inline]
 __bpf_probe_register kernel/trace/bpf_trace.c:2348 [inline]
 bpf_probe_register+0x13f/0x1d0 kernel/trace/bpf_trace.c:2354
 bpf_raw_tp_link_attach+0x3d1/0x550 kernel/bpf/syscall.c:3367
 bpf_raw_tracepoint_open+0x258/0x480 kernel/bpf/syscall.c:3394
 __sys_bpf+0x4d1/0x780 kernel/bpf/syscall.c:5044
 __do_sys_bpf kernel/bpf/syscall.c:5106 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5104 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5104
 x64_sys_call+0x488/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa73c18e929
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa73d0d8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fa73c3b5fa0 RCX: 00007fa73c18e929
RDX: 0000000000000010 RSI: 0000200000000040 RDI: 0000000000000011
RBP: 00007fa73c210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa73c3b5fa0 R15: 00007ffc201e75e8
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1195 Comm: kworker/1:11 Not tainted 6.1.141-syzkaller-00033-g36d69f6a49eb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: wg-crypt-wg2 wg_packet_tx_worker
RIP: 0010:native_halt arch/x86/include/asm/irqflags.h:57 [inline]
RIP: 0010:halt arch/x86/include/asm/irqflags.h:98 [inline]
RIP: 0010:kvm_wait+0xcc/0x140 arch/x86/kernel/kvm.c:1058
Code: 20 f6 44 24 21 02 75 24 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 48 0f b6 07 40 38 f0 75 a6 66 90 0f 00 2d b5 ae 13 04 f4 <eb> 9a fa 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 3f 0f b6 07
RSP: 0018:ffffc900001af480 EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffff8881f7127c40 RCX: ffffffff84f06582
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff8881f7127c40
RBP: ffffc900001af510 R08: dffffc0000000000 R09: ffffed103ee24f89
R10: ffffed103ee24f89 R11: 1ffff1103ee24f88 R12: 1ffff1103ee20001
R13: ffff8881f7138c94 R14: dffffc0000000000 R15: 1ffff92000035e90
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 0000000130100000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x108/0x110 kernel/locking/spinlock.c:162
 lock_timer_base+0x127/0x270 kernel/time/timer.c:1005
 __mod_timer+0x10a/0xb30 kernel/time/timer.c:1078
 add_timer+0x68/0x80 kernel/time/timer.c:1218
 __queue_delayed_work+0x173/0x200 kernel/workqueue.c:1686
 queue_delayed_work_on+0xdb/0x150 kernel/workqueue.c:1711
 queue_delayed_work include/linux/workqueue.h:525 [inline]
 schedule_delayed_monitor_work kernel/rcu/tree.c:3216 [inline]
 kvfree_call_rcu+0x436/0x7a0 kernel/rcu/tree.c:3472
 trie_delete_elem+0x572/0x720 kernel/bpf/lpm_trie.c:545
 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e
 bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline]
 bpf_trace_run3+0x113/0x270 kernel/trace/bpf_trace.c:2323
 __bpf_trace_timer_start+0x2b/0x40 include/trace/events/timer.h:53
 trace_timer_start include/trace/events/timer.h:53 [inline]
 enqueue_timer+0x337/0x480 kernel/time/timer.c:615
 __mod_timer+0x79f/0xb30 kernel/time/timer.c:-1
 mod_timer+0x1f/0x30 kernel/time/timer.c:1172
 sk_reset_timer+0x22/0xb0 net/core/sock.c:3390
 inet_csk_reset_xmit_timer include/net/inet_connection_sock.h:-1 [inline]
 tcp_reset_xmit_timer include/net/tcp.h:1366 [inline]
 tcp_schedule_loss_probe+0x441/0x860 net/ipv4/tcp_output.c:2792
 tcp_set_xmit_timer net/ipv4/tcp_input.c:3265 [inline]
 tcp_ack+0x3939/0x5cd0 net/ipv4/tcp_input.c:3991
 tcp_rcv_established+0x72d/0x19f0 net/ipv4/tcp_input.c:6099
 tcp_v4_do_rcv+0x446/0xa10 net/ipv4/tcp_ipv4.c:1683
 tcp_v4_rcv+0x233c/0x2a80 net/ipv4/tcp_ipv4.c:2114
 ip_protocol_deliver_rcu+0x325/0x6e0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x24e/0x410 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip_local_deliver+0x1d8/0x320 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:463 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0x773/0x880 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3da/0x420 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5628 [inline]
 __netif_receive_skb_list_core+0x59e/0x770 net/core/dev.c:5676
 __netif_receive_skb_list net/core/dev.c:5728 [inline]
 netif_receive_skb_list_internal+0x7d2/0xa60 net/core/dev.c:5819
 gro_normal_list include/net/gro.h:433 [inline]
 napi_complete_done+0x36f/0x790 net/core/dev.c:6160
 virtqueue_napi_complete drivers/net/virtio_net.c:403 [inline]
 virtnet_poll+0x991/0x1150 drivers/net/virtio_net.c:1687
 __napi_poll+0xd0/0x5e0 net/core/dev.c:6594
 napi_poll net/core/dev.c:6661 [inline]
 net_rx_action+0x49b/0xaa0 net/core/dev.c:6775
 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
 __do_softirq+0xb/0xd kernel/softirq.c:680
 do_softirq+0xc6/0x120 kernel/softirq.c:524
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x75/0x80 kernel/softirq.c:448
 __raw_read_unlock_bh include/linux/rwlock_api_smp.h:257 [inline]
 _raw_read_unlock_bh+0x29/0x30 kernel/locking/spinlock.c:284
 wg_socket_send_skb_to_peer+0x172/0x1d0 drivers/net/wireguard/socket.c:184
 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
 wg_packet_tx_worker+0x1ce/0x4e0 drivers/net/wireguard/send.c:276
 process_one_work+0x71f/0xc40 kernel/workqueue.c:2299
 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2446
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/28 12:11 android14-6.1 36d69f6a49eb fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 BUG: soft lockup in tcp_tasklet_func
* Struck through repros no longer work on HEAD.