syzbot


INFO: task hung in io_uring_register (6)

Status: auto-obsoleted due to no activity on 2026/04/16 06:19
Subsystems: io-uring
[Documentation on labels]
First crash: 91d, last: 91d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
54656a39-afb8-4f16-a779-984e414bfcec repro 💥 INFO: task hung in io_uring_register (6) 2026/03/07 21:27 2026/03/07 21:27 2026/03/07 21:44 31e9c887f7dc24e04b3ca70d0d54fc34141844b0 Error 504, Message: Deadline expired before operation could complete., Status: DEADLINE_EXCEEDED, Details: [map[@type:type.googleapis.com/google.rpc.DebugInfo detail:[ORIGINAL ERROR] generic::deadline_exceeded: [original: beyond::dependency::DEADLINE_EXCEEDED] Request deadline exceeded before prefill finished.; Failed while executing Op 'Prefill'; Failed to close the streaming context; status = DEADLINE_EXCEEDED: Request deadline exceeded before prefill finished.; Failed while executing Op 'Prefill' [type.googleapis.com/stairways.orch.ErrorLoc='learning/serving/servables/wiz/orch_wiz_servable.cc:941'] === Source Location Trace: === learning/brain/research/stairways/orchestrator/leaf/chain_stub.cc:125 learning/serving/servables/wiz/orch_wiz_servable.cc:970 ; Failed to run inference for model: go/debugonly name: "prod-common-global__/aistudio/gemini-v4m-rev22-riftrunner-sc__main__/aistudio/gemini-v4m-rev22-riftrunner-sc__2026020501__prefill__variant__9bf6d6a9-45b2-4e76-b4bb-a35911ca2292" version { value: 1 } signature_name: "serving_default" ; [model=/aistudio/gemini-v4m-rev22-riftrunner-sc,target=PredictionService]; for endpoint: [google.rpc.error_details_ext] { message: "Deadline expired before operation could complete." details { type_url: "type.googleapis.com/language_labs.genai.debug.GeminiApiDebugInfo" value: "\222\001\235\007\n\375\006Request deadline exceeded before prefill finished.; Failed while executing Op \'Prefill\'; Failed to close the streaming context; status = DEADLINE_EXCEEDED: Request deadline exceeded before prefill finished.; Failed while executing Op \'Prefill\' [type.googleapis.com/stairways.orch.ErrorLoc=\'learning/serving/servables/wiz/orch_wiz_servable.cc:941\']\n=== Source Location Trace: ===\nlearning/brain/research/stairways/orchestrator/leaf/chain_stub.cc:125\nlearning/serving/servables/wiz/orch_wiz_servable.cc:970\n; Failed to run inference for model: go/debugonly \nname: \"prod-common-global__/aistudio/gemini-v4m-rev22-riftrunner-sc__main__/aistudio/gemini-v4m-rev22-riftrunner-sc__2026020501__prefill__variant__9bf6d6a9-45b2-4e76-b4bb-a35911ca2292\"\nversion {\n value: 1\n}\nsignature_name: \"serving_default\"\n; [model=/aistudio/gemini-v4m-rev22-riftrunner-sc,target=PredictionService]; for endpoint: \022\033net/rpc/rpc-status.cc:562:0" } } 525002922 { 3 { 1: "/aistudio/gemini-v4m-rev22-riftrunner-sc" } 6 { 5 { 1 { 1: "/aistudio/gemini-v4m-rev22-riftrunner-sc" 3: "serving_default" } 2: 131072 3: 1 } 6 { 1: 1 2: 1 3: 0 4: "Retry after error: decode timeout, from active slot 143; Failed while executing Op \'Decode\'; Failed to close the streaming context; status = DEADLINE_EXCEEDED: decode timeout, from active slot 143; Failed while executing Op \'Decode\' [type.googleapis.com/stairways.orch.ErrorLoc=\'learning/serving/servables/wiz/orch_wiz_servable.cc:1027\']\n=== Source Location Trace: === \nlearning/brain/research/stairways/orchestrator/leaf/chain_stub.cc:125\nlearning/serving/servables/wiz/orch_wiz_servable.cc:1037\n; Failed to run inference for model: go/debugonly \nname: \"prod-common-global__/aistudio/gemini-v4m-rev22-riftrunner-sc__main__/aistudio/gemini-v4m-rev22-riftrunner-sc__2026020501__prefill__variant-sha__7c81fe08-a342-470c-ba15-2c3a0d80988c\"\nversion {\n value: 1\n}\nsignature_name: \"serving_default\"\n; [model=/aistudio/gemini-v4m-rev22-riftrunner-sc,target=PredictionService]; for endpoint: " 4: "Max retries reached. Final error: Request deadline exceeded before prefill finished.; Failed while executing Op \'Prefill\'; Failed to close the streaming context; status = DEADLINE_EXCEEDED: Request deadline exceeded before prefill finished.; Failed while executing Op \'Prefill\' [type.googleapis.com/stairways.orch.ErrorLoc=\'learning/serving/servables/wiz/orch_wiz_servable.cc:941\']\n=== Source Location Trace: ===\nlearning/brain/research/stairways/orchestrator/leaf/chain_stub.cc:125\nlearning/serving/servables/wiz/orch_wiz_servable.cc:970\n; Failed to run inference for model: go/debugonly \nname: \"prod-common-global__/aistudio/gemini-v4m-rev22-riftrunner-sc
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in io_uring_register fs 1 1 1597d 1597d 0/29 auto-closed as invalid on 2022/04/01 07:34
upstream INFO: task hung in io_uring_register (5) io-uring 1 1 643d 643d 0/29 auto-obsoleted due to no activity on 2024/10/11 10:45
upstream INFO: task hung in io_uring_register (3) io-uring 1 syz error error 2 1147d 1143d 0/29 auto-obsoleted due to no activity on 2023/06/25 17:40
upstream INFO: task hung in io_uring_register (4) io-uring 1 1 765d 765d 0/29 auto-obsoleted due to no activity on 2024/06/10 23:45
upstream INFO: task hung in io_uring_register (2) io-uring 1 1 1287d 1287d 0/29 auto-obsoleted due to no activity on 2023/01/17 13:12
upstream INFO: task hung in sys_io_uring_register fs 1 1 1576d 1572d 0/29 auto-closed as invalid on 2022/03/23 08:02
upstream INFO: task hung in sys_io_uring_register (2) io-uring 1 syz error error 2 1146d 1143d 0/29 auto-obsoleted due to no activity on 2023/06/25 22:43
upstream INFO: task hung in sys_io_uring_register (3) io-uring 1 1 587d 587d 0/29 auto-obsoleted due to no activity on 2024/12/06 01:30
linux-5.15 INFO: task hung in sys_io_uring_register 1 1 747d 747d 0/3 auto-obsoleted due to no activity on 2024/07/09 12:11

Sample crash report:
INFO: task syz.5.718:9035 blocked for more than 156 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.718       state:D stack:28728 pid:9035  tgid:9021  ppid:6789   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 __do_sys_io_uring_register io_uring/register.c:920 [inline]
 __se_sys_io_uring_register+0x184/0x1200 io_uring/register.c:898
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f81a298f749
RSP: 002b:00007f81a0b04038 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 00007f81a2be6090 RCX: 00007f81a298f749
RDX: 00002000000001c0 RSI: 0000000000000018 RDI: 0000000000000003
RBP: 00007f81a2a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f81a2be6128 R14: 00007f81a2be6090 R15: 00007f81a2d0fa28
 </TASK>

Showing all locks held in the system:
2 locks held by kthreadd/2:
4 locks held by kworker/0:0/9:
 #0: ffff8880334c3948 ((wq_completion)wg-kex-wg1#6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff8880334c3948 ((wq_completion)wg-kex-wg1#6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc900000e7bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc900000e7bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff88807d1c5308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598
 #3: ffff88805c2a5c60 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632
4 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
3 locks held by kworker/1:0/24:
1 lock held by khungtaskd/31:
 #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/34:
 #0: ffff8880293e0948 ((wq_completion)wg-kex-wg2#9){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff8880293e0948 ((wq_completion)wg-kex-wg2#9){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc90000aa7bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc90000aa7bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff888064d21308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x105/0x750 drivers/net/wireguard/noise.c:529
 #3: ffff888031b65c60 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x116/0x750 drivers/net/wireguard/noise.c:530
2 locks held by kworker/u8:3/37:
3 locks held by kworker/0:2/40:
4 locks held by kworker/1:1/45:
4 locks held by kworker/u8:4/62:
 #0: ffff8880545e3948 ((wq_completion)wg-kex-wg0#11){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff8880545e3948 ((wq_completion)wg-kex-wg0#11){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc9000212fbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000212fbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff888064961308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x105/0x750 drivers/net/wireguard/noise.c:529
 #3: ffff888031b60d20 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x116/0x750 drivers/net/wireguard/noise.c:530
3 locks held by kworker/u8:5/148:
4 locks held by kworker/0:3/980:
4 locks held by kworker/u8:6/1001:
 #0: ffff888026804948 ((wq_completion)wg-kex-wg2#17){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff888026804948 ((wq_completion)wg-kex-wg2#17){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc90003a8fbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc90003a8fbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff88805dae9308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x105/0x750 drivers/net/wireguard/noise.c:529
 #3: ffff88807f4de648 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x116/0x750 drivers/net/wireguard/noise.c:530
3 locks held by kworker/u8:7/1106:
4 locks held by kworker/u8:8/1140:
4 locks held by kworker/u8:9/1887:
3 locks held by kworker/u8:10/2951:
4 locks held by kworker/u8:11/2975:
 #0: ffff888059808948 ((wq_completion)wg-kex-wg0#15){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff888059808948 ((wq_completion)wg-kex-wg0#15){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc9000b9f7bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000b9f7bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff88807ca51308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x105/0x750 drivers/net/wireguard/noise.c:529
 #3: ffff88807f4daad8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x116/0x750 drivers/net/wireguard/noise.c:530
3 locks held by kworker/u8:12/2977:
3 locks held by kworker/u8:13/2986:
2 locks held by kworker/R-bat_e/3412:
3 locks held by kworker/u8:14/3548:
2 locks held by kworker/1:2/5142:
1 lock held by klogd/5190:
2 locks held by udevd/5201:
2 locks held by getty/5595:
 #0: ffff88803499d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5819:
7 locks held by kworker/u9:4/5836:
 #0: ffff888033002148 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff888033002148 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc900042afbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc900042afbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff88807efb4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
 #3: ffff88807efb40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30 net/bluetooth/hci_sync.c:5703
 #4: ffffffff8f484608 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2128 [inline]
 #4: ffffffff8f484608 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x340 net/bluetooth/hci_conn.c:1336
 #5: ffff88801d690b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763
 #6: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #6: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2b1/0x6e0 kernel/rcu/tree_exp.h:956
5 locks held by kworker/u9:5/5837:
 #0: ffff88805a130148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88805a130148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc900042cfbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc900042cfbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff888054930ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
 #3: ffff8880549300c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30 net/bluetooth/hci_sync.c:5703
 #4: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #4: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:956
5 locks held by kworker/1:4/5882:
2 locks held by kworker/1:6/5913:
4 locks held by kworker/0:4/5920:
2 locks held by kworker/0:5/5922:
3 locks held by kworker/0:6/5923:
3 locks held by kworker/1:7/5924:
3 locks held by kworker/u8:15/5939:
3 locks held by kworker/u8:16/5958:
4 locks held by kworker/u8:17/5965:
3 locks held by kworker/u8:18/5981:
5 locks held by kworker/0:8/6104:
3 locks held by kworker/u8:19/6128:
2 locks held by kworker/1:8/6363:
3 locks held by kworker/1:9/6373:
4 locks held by kworker/u8:20/6407:
 #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc9001a76fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9001a76fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffffffff8f304f70 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670
 #3: ffffffff8df474c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816
3 locks held by kworker/u8:21/6410:
4 locks held by kworker/0:9/6463:
3 locks held by kworker/u8:22/6473:
3 locks held by kworker/1:11/6474:
4 locks held by kworker/0:10/6654:
3 locks held by syz-executor/6789:
4 locks held by kworker/1:12/6790:
 #0: ffff88805b89a948 ((wq_completion)wg-kex-wg0#16){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88805b89a948 ((wq_completion)wg-kex-wg0#16){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc9000ed7fbc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000ed7fbc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff88807ca51308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598
 #3: ffff88807f4daad8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632
2 locks held by kworker/0:11/6791:
4 locks held by syz-executor/6796:
1 lock held by syz-executor/7623:
3 locks held by kworker/u8:23/7651:
4 locks held by kworker/1:13/8996:
 #0: ffff88805b9e0148 ((wq_completion)wg-kex-wg0#6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88805b9e0148 ((wq_completion)wg-kex-wg0#6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc9000524fbc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000524fbc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff88806b14d308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598
 #3: ffff88805c2a3ea8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632
3 locks held by syz.5.718/9023:
1 lock held by syz.5.718/9035:
 #0: ffff88806ad660a8 (&ctx->uring_lock){+.+.}-{4:4}, at: __do_sys_io_uring_register io_uring/register.c:920 [inline]
 #0: ffff88806ad660a8 (&ctx->uring_lock){+.+.}-{4:4}, at: __se_sys_io_uring_register+0x184/0x1200 io_uring/register.c:898
1 lock held by syz.1.719/9026:
2 locks held by syz.7.720/9027:
1 lock held by syz.7.720/9030:
1 lock held by syz.7.720/9032:
3 locks held by sed/9034:
3 locks held by kworker/0:12/9037:
4 locks held by kworker/1:14/9038:
4 locks held by kworker/u8:25/9040:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xf95/0xfe0 kernel/hung_task.c:515
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5882 Comm: kworker/1:4 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-kex-wg1 wg_packet_handshake_receive_worker
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:751
Code: e8 bb 2d b3 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 0d 9b 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 7c 1d 80 00 48 c7 c3 d8 76 81 92 49 03 1e 48 89
RSP: 0018:ffffc90000a07a98 EFLAGS: 00000246
RAX: 1ffffffff1b361bb RBX: 0000000000000001 RCX: 0000000000000102
RDX: 0000000000000000 RSI: ffffffff8bc08740 RDI: ffffffff8bc08700
RBP: ffffffff8173fdd5 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000a07c78 R11: ffffffff81acf4d0 R12: 0000000000000002
R13: ffffffff8df41aa0 R14: ffffffff8d9b0dd8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125f1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001f6030 CR3: 0000000078a82000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x5f/0x340 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 skb_ext_maybe_cow net/core/skbuff.c:7043 [inline]
 skb_ext_add+0x1b6/0x8f0 net/core/skbuff.c:7118
 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:169 [inline]
 br_nf_forward_ip+0xc6/0x7e0 net/bridge/br_netfilter_hooks.c:681
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK+0x215/0x3c0 include/linux/netfilter.h:316
 __br_forward+0x397/0x540 net/bridge/br_forward.c:115
 deliver_clone net/bridge/br_forward.c:131 [inline]
 maybe_deliver+0xb5/0x160 net/bridge/br_forward.c:191
 br_flood+0x31a/0x6a0 net/bridge/br_forward.c:238
 br_handle_frame_finish+0x15a3/0x1c90 net/bridge/br_input.c:229
 br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1
 br_nf_pre_routing_finish_ipv6+0x999/0xd60 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0x96e/0x14f0 net/bridge/br_input.c:442
 __netif_receive_skb_core+0x95f/0x2f90 net/core/dev.c:6039
 __netif_receive_skb_one_core net/core/dev.c:6150 [inline]
 __netif_receive_skb+0x72/0x380 net/core/dev.c:6265
 process_backlog+0x54f/0x1340 net/core/dev.c:6617
 __napi_poll+0xae/0x320 net/core/dev.c:7681
 napi_poll net/core/dev.c:7744 [inline]
 net_rx_action+0x64a/0xe00 net/core/dev.c:7896
 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 blake2s_compress+0xe0/0x1e30 lib/crypto/x86/blake2s.h:42
 blake2s_final+0x116/0x270 lib/crypto/blake2s.c:142
 hmac+0x293/0x330 drivers/net/wireguard/noise.c:333
 kdf+0x105/0x270 drivers/net/wireguard/noise.c:367
 mix_dh drivers/net/wireguard/noise.c:413 [inline]
 wg_noise_handshake_consume_initiation+0x220/0x900 drivers/net/wireguard/noise.c:608
 wg_receive_handshake_packet drivers/net/wireguard/receive.c:144 [inline]
 wg_packet_handshake_receive_worker+0x5ee/0xfc0 drivers/net/wireguard/receive.c:213
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/16 06:16 upstream 603c05a1639f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in io_uring_register
* Struck through repros no longer work on HEAD.