INFO: rcu detected stall in wg_packet_handshake_send_worker (2)

Status: auto-obsoleted due to no activity on 2026/02/18 00:47
Reported-by: syzbot+6405dace9292064856f5@syzkaller.appspotmail.com
First crash: 267d, last: 267d
▶ ▼ Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in wg_packet_handshake_send_worker (6) crypto 1 1 469d 469d 0/29 auto-obsoleted due to no activity on 2025/07/21 04:05
upstream INFO: rcu detected stall in wg_packet_handshake_send_worker (4) wireguard 1 1 1113d 1113d 0/29 auto-obsoleted due to no activity on 2023/10/15 22:40
upstream INFO: rcu detected stall in wg_packet_handshake_send_worker net 1 1 2287d 2287d 0/29 auto-closed as invalid on 2020/07/28 10:33
linux-5.15 INFO: rcu detected stall in wg_packet_handshake_send_worker 1 1 848d 848d 0/3 auto-obsoleted due to no activity on 2024/07/16 21:11
upstream INFO: rcu detected stall in wg_packet_handshake_send_worker (5) wireguard 1 1 976d 976d 0/29 auto-obsoleted due to no activity on 2024/02/29 10:43
linux-5.15 BUG: soft lockup in wg_packet_handshake_send_worker 1 2 602d 625d 0/3 auto-obsoleted due to no activity on 2025/03/20 05:34
upstream INFO: rcu detected stall in wg_packet_handshake_send_worker (3) kernel 1 1 1322d 1322d 0/29 auto-obsoleted due to no activity on 2023/04/12 00:54
linux-6.1 INFO: rcu detected stall in wg_packet_handshake_send_worker 1 1 794d 794d 0/3 auto-obsoleted due to no activity on 2024/09/09 01:47
upstream INFO: rcu detected stall in wg_packet_handshake_send_worker (2) net 1 1 2194d 2194d 0/29 auto-closed as invalid on 2020/10/29 22:12
android-5-15 BUG: soft lockup in wg_packet_handshake_send_worker 1 2 1110d 1117d 0/2 auto-obsoleted due to no activity on 2023/10/18 09:06
android-5-10 BUG: soft lockup in wg_packet_handshake_send_worker 1 6 1083d 1123d 0/2 auto-obsoleted due to no activity on 2023/11/15 02:30

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=511/1/0x4000000000000002 softirq=20838/20838 fqs=0 
	(detected by 1, t=10506 jiffies, g=28065, q=898)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4477 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:-1 [inline]
RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:344 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:895 [inline]
RIP: 0010:trace_lock_release include/trace/events/lock.h:58 [inline]
RIP: 0010:lock_release+0x7d8/0x870 kernel/locking/lockdep.c:5634
Code: 83 fb 08 0f 83 af 00 00 00 89 d8 c1 e8 06 48 8d 3c c5 28 9d 69 8d be 08 00 00 00 e8 72 b2 5f 00 89 d8 48 0f a3 05 d0 19 0d 0c <4d> 89 f5 4d 89 e7 0f 83 de f8 ff ff 65 ff 05 5d ec a5 7e 48 8b 1d
RSP: 0018:ffffc900000071c0 EFLAGS: 00000057
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815c834e
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d699d28
RBP: ffffc900000072d0 R08: dffffc0000000000 R09: fffffbfff1ad33a6
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: 1ffff92000000e44
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000000e44
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98c91f0ff8 CR3: 000000000be8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __perf_output_begin kernel/events/ring_buffer.c:262 [inline]
 perf_output_begin_forward+0x793/0xa30 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7804 [inline]
 perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_swevent_overflow kernel/events/core.c:9591 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
RAX: eeccebaa25844000 RBX: 1ffff92000000f60 RCX: eeccebaa25844000
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: fffffbfff1ff7c39
R10: fffffbfff1ff7c39 R11: 1ffffffff1ff7c38 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x132/0x1b0 kernel/softirq.c:408
Code: 8a e8 92 0b 61 08 65 66 8b 05 8a 25 bb 7e 66 85 c0 75 54 bf 01 00 00 00 e8 ab fe 08 00 e8 66 76 35 00 fb 65 8b 05 36 fc b9 7e <85> c0 75 05 e8 e5 06 b8 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc9000347fa20 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 0000000000000200 RCX: eeccebaa25844000
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc9000347fab0 R08: dffffc0000000000 R09: fffffbfff1ff7c39
R10: fffffbfff1ff7c39 R11: 1ffffffff1ff7c38 R12: ffffffff85282c25
R13: ffff8880790a1c20 R14: dffffc0000000000 R15: 1ffff9200068ff44
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:42 [inline]
 wg_packet_handshake_send_worker+0x1e0/0x310 drivers/net/wireguard/send.c:51
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g28065 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=17101
rcu: rcu_preempt kthread starved for 10506 jiffies! g28065 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:27904 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4477 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:check_preemption_disabled+0x3/0x110 lib/smp_processor_id.c:13
Code: c7 c7 20 dd 12 8a e8 2c 01 00 00 65 ff 0d 91 d6 59 76 5b c3 00 00 cc 48 c7 c7 20 e5 59 8a 48 c7 c6 60 e5 59 8a eb 00 55 41 57 <41> 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65
RSP: 0018:ffffc90000007280 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff888029bf3b80 RCX: 0000000000000001
RDX: 0000000000000100 RSI: ffffffff8a0b2f00 RDI: ffffffff8a59e580
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1ff7c19
R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: 0000000000000002
R13: 0000000000000046 R14: ffffffff8c11c760 R15: ffff888029bf46c0
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98c91f0ff8 CR3: 000000000be8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
 lock_is_held_type+0x100/0x190 kernel/locking/lockdep.c:5667
 __perf_output_begin kernel/events/ring_buffer.c:170 [inline]
 perf_output_begin_forward+0x1a6/0xa30 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7804 [inline]
 perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_swevent_overflow kernel/events/core.c:9591 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
RAX: eeccebaa25844000 RBX: 1ffff92000000f60 RCX: eeccebaa25844000
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: fffffbfff1ff7c39
R10: fffffbfff1ff7c39 R11: 1ffffffff1ff7c38 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x132/0x1b0 kernel/softirq.c:408
Code: 8a e8 92 0b 61 08 65 66 8b 05 8a 25 bb 7e 66 85 c0 75 54 bf 01 00 00 00 e8 ab fe 08 00 e8 66 76 35 00 fb 65 8b 05 36 fc b9 7e <85> c0 75 05 e8 e5 06 b8 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc9000347fa20 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 0000000000000200 RCX: eeccebaa25844000
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc9000347fab0 R08: dffffc0000000000 R09: fffffbfff1ff7c39
R10: fffffbfff1ff7c39 R11: 1ffffffff1ff7c38 R12: ffffffff85282c25
R13: ffff8880790a1c20 R14: dffffc0000000000 R15: 1ffff9200068ff44
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:42 [inline]
 wg_packet_handshake_send_worker+0x1e0/0x310 drivers/net/wireguard/send.c:51
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/10 00:46 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in wg_packet_handshake_send_worker
* Struck through repros no longer work on HEAD.