INFO: rcu detected stall in wg_packet_tx_worker (5)

Status: auto-obsoleted due to no activity on 2026/08/29 03:32
Subsystems: wireguard
Labels: prio:high
[Documentation on labels]
First crash: 141d, last: 101d
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ID Workflow Result Correct Bug Created Started Finished Revision
525f0e4b assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: rcu detected stall in wg_packet_tx_worker (5) 2026/05/24 10:03 2026/05/24 10:03 2026/05/24 10:56 c69befb3
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in wg_packet_tx_worker net 1 syz, C done 24 2273d 2326d 15/29 fixed on 2020/07/17 17:58
upstream INFO: rcu detected stall in wg_packet_tx_worker (2) net 1 4 2128d 2223d 0/29 auto-closed as invalid on 2021/02/08 20:10
linux-5.15 INFO: rcu detected stall in wg_packet_tx_worker 1 1 824d 824d 0/3 auto-obsoleted due to no activity on 2024/09/14 07:48
upstream INFO: rcu detected stall in wg_packet_tx_worker (4) net 1 1 1748d 1748d 0/29 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in wg_packet_tx_worker (3) net 1 syz, C inconclusive 5 1849d 1832d 20/29 fixed on 2021/11/10 00:50
linux-6.1 BUG: soft lockup in wg_packet_tx_worker 1 2 619d 648d 0/3 auto-obsoleted due to no activity on 2025/04/07 20:48
linux-5.15 BUG: soft lockup in wg_packet_tx_worker origin:lts-only 1 syz, C error 1 186d 661d 0/3 upstream: reported C repro on 2024/11/16 16:23
android-5-10 BUG: soft lockup in wg_packet_tx_worker 1 5 1111d 1160d 0/2 auto-obsoleted due to no activity on 2023/11/22 23:32
upstream BUG: soft lockup in wg_packet_tx_worker (3) net 1 1 525d 519d 0/29 auto-obsoleted due to no activity on 2025/07/10 22:54
android-6-1 BUG: soft lockup in wg_packet_tx_worker 1 3 1025d 1048d 0/2 auto-obsoleted due to no activity on 2024/02/16 07:09
upstream BUG: soft lockup in wg_packet_tx_worker (2) wireguard 1 5 648d 779d 0/29 closed as invalid on 2025/02/06 13:09
android-5-15 BUG: soft lockup in wg_packet_tx_worker 1 1 1120d 1120d 0/2 auto-obsoleted due to no activity on 2023/11/14 01:23
android-5-15 BUG: soft lockup in wg_packet_tx_worker (2) 1 1 875d 875d 0/2 auto-obsoleted due to no activity on 2024/07/15 09:44

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=141c/1/0x4000000000000000 softirq=148052/148053 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P19804/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=135649, q=673 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5990 Comm: kworker/1:7 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: wg-crypt-wg0 wg_packet_tx_worker
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:114 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x6e/0x1e0 mm/kasan/generic.c:200
Code: 4c 8d 54 37 ff 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 <48> 89 da 48 29 ea 48 83 fa 10 0f 8e db 00 00 00 41 89 eb 41 83 e3
RSP: 0018:ffffc90000a08dd0 EFLAGS: 00000082
RAX: ffffed10170a5098 RBX: ffffed10170a5099 RCX: ffffffff81e5b029
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880b85284c0
RBP: ffffed10170a5098 R08: 0000000000000001 R09: ffffed10170a5098
R10: ffff8880b85284c3 R11: 0000000000000001 R12: 1ffff920001411bf
R13: ffff8880b85284d0 R14: dffffc0000000000 R15: ffff8880b8528650
FS:  0000000000000000(0000) GS:ffff8881243e7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b308f0ff8 CR3: 0000000035a96000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock+0x119/0x260 kernel/locking/spinlock_debug.c:116
 __run_hrtimer kernel/time/hrtimer.c:1934 [inline]
 __hrtimer_run_queues+0x1bd/0xa00 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch.isra.0+0x2d3/0x1010 kernel/sched/core.c:5244
Code: 2f 0a 00 00 41 c7 87 e0 0d 00 00 00 00 00 00 0f 1f 44 00 00 49 8d 7f 48 e8 7a ee c5 09 e8 55 8a 3b 00 fb 48 8d bb a8 16 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84
RSP: 0018:ffffc90004627938 EFLAGS: 00000202
RAX: 00000000002d6d73 RBX: ffff88802ff68000 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffffff8df562a9 RDI: ffff88802ff696a8
RBP: ffffc90004627990 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888046548000
R13: 0000000000000000 R14: ffffffff90dc1ae4 R15: ffff8880b853b240
 context_switch kernel/sched/core.c:5390 [inline]
 __schedule+0x10f1/0x6820 kernel/sched/core.c:7188
 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7369
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:457
 wg_socket_send_skb_to_peer+0x145/0x210 drivers/net/wireguard/socket.c:183
 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
 wg_packet_tx_worker+0x199/0x7f0 drivers/net/wireguard/send.c:276
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:syz.5.3369      state:R  running task     stack:23016 pid:19804 tgid:19803 ppid:17167  task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_is_held_type+0xf5/0x140 kernel/locking/lockdep.c:5945
Code: ff ff ff ff 65 0f c1 15 f1 a5 7a 08 83 fa 01 8b 44 24 04 75 2d 9c 5a 80 e6 02 75 47 41 f7 c5 00 02 00 00 74 01 fb 48 83 c4 08 <5b> 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc e9 17 39 03 00 31 c0
RSP: 0018:ffffc9000fbaeb20 EFLAGS: 00000292
RAX: 0000000000000001 RBX: ffffffff8e7e5460 RCX: 0000000000000001
RDX: 0000000000000046 RSI: ffffffff8df30d5f RDI: ffffffff8c1c1300
RBP: ffff888026d3a500 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffff
R13: 0000000000000246 R14: ffff888026d3b180 R15: 0000000000000006
 kernfs_root+0x20e/0x2a0 fs/kernfs/kernfs-internal.h:75
 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:108 [inline]
 kernfs_rcu_name fs/kernfs/kernfs-internal.h:118 [inline]
 kernfs_sd_compare fs/kernfs/dir.c:366 [inline]
 kernfs_link_sibling+0x2f1/0x850 fs/kernfs/dir.c:397
 kernfs_add_one+0x1e7/0x850 fs/kernfs/dir.c:845
 __kernfs_create_file+0x295/0x350 fs/kernfs/file.c:1086
 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x593/0xf40 fs/sysfs/group.c:189
 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:229
 setup_gid_attrs drivers/infiniband/core/sysfs.c:1118 [inline]
 ib_setup_port_attrs+0x41f/0x600 drivers/infiniband/core/sysfs.c:1394
 add_one_compat_dev+0x5b3/0x820 drivers/infiniband/core/device.c:978
 add_compat_devs drivers/infiniband/core/device.c:1036 [inline]
 enable_device_and_get+0x33c/0x3f0 drivers/infiniband/core/device.c:1347
 ib_register_device drivers/infiniband/core/device.c:1460 [inline]
 ib_register_device+0x8eb/0xde0 drivers/infiniband/core/device.c:1406
 rxe_register_device+0x277/0x360 drivers/infiniband/sw/rxe/rxe_verbs.c:1556
 rxe_net_add+0x95/0xf0 drivers/infiniband/sw/rxe/rxe_net.c:618
 rxe_newlink+0x70/0x150 drivers/infiniband/sw/rxe/rxe.c:234
 nldev_newlink+0x3ae/0x620 drivers/infiniband/core/nldev.c:1797
 rdma_nl_rcv_msg+0x392/0x6f0 drivers/infiniband/core/netlink.c:195
 rdma_nl_rcv_skb.constprop.0.isra.0+0x2cb/0x410 drivers/infiniband/core/netlink.c:239
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
 __sys_sendmsg+0x170/0x220 net/socket.c:2784
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1e6ed9c819
RSP: 002b:00007f1e6fd3a028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1e6f015fa0 RCX: 00007f1e6ed9c819
RDX: 0000000004008010 RSI: 0000200000000380 RDI: 0000000000000005
RBP: 00007f1e6ee32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1e6f016038 R14: 00007f1e6f015fa0 R15: 00007fffe6b4a738
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g135649 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27928 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 3578 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 db ef d9 f5 cc
RSP: 0018:ffffc900101ef868 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fcf98d
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88803648ca00
RBP: ffff8880b8540f40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81e9 R14: 0000000000000001 R15: ffff8880b843c5c0
FS:  0000000000000000(0000) GS:ffff8881242e7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efc2c9e9f00 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0x5ad/0x1700 kernel/smp.c:892
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
 smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x37a/0x550 kernel/jump_label.c:910
 static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:906 [inline]
 toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:898
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/20 16:52 upstream c1f49dea2b8f e65da4ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in wg_packet_tx_worker
2026/05/31 03:27 linux-next f7af91adc230 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in wg_packet_tx_worker
2026/05/20 00:19 linux-next 6a50ba100ace 0909d65f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in wg_packet_tx_worker
* Struck through repros no longer work on HEAD.