syzbot


INFO: task hung in netdev_run_todo (2)

Status: premoderation: reported on 2026/01/22 03:02
Reported-by: syzbot+f4c9b9509664219a17ad@syzkaller.appspotmail.com
First crash: 67d, last: 3d18h
Similar bugs (17)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in netdev_run_todo (3) 1 15 1239d 1555d 0/1 auto-obsoleted due to no activity on 2023/03/07 08:19
linux-6.6 INFO: task hung in netdev_run_todo 1 1 206d 206d 0/2 auto-obsoleted due to no activity on 2025/12/14 15:00
linux-5.15 INFO: task hung in netdev_run_todo (3) 1 1 94d 94d 0/3 upstream: reported on 2025/12/26 15:48
upstream INFO: task hung in netdev_run_todo net 1 12 2413d 2968d 0/29 closed as invalid on 2019/10/23 07:29
linux-4.19 INFO: task hung in netdev_run_todo (2) 1 3 2046d 2094d 0/1 auto-closed as invalid on 2020/12/20 04:57
android-44 INFO: task hung in netdev_run_todo 1 1 2907d 2907d 0/2 auto-closed as invalid on 2019/02/22 12:49
upstream INFO: task hung in netdev_run_todo (4) wireless 1 790 9d21h 536d 0/29 upstream: reported on 2024/10/09 19:06
linux-4.19 INFO: task hung in netdev_run_todo 1 1 2372d 2372d 0/1 auto-closed as invalid on 2020/01/29 06:48
upstream INFO: task hung in netdev_run_todo (3) net 1 24 650d 688d 0/29 auto-obsoleted due to no activity on 2024/08/07 04:24
linux-5.15 INFO: task hung in netdev_run_todo 1 1 885d 885d 0/3 auto-obsoleted due to no activity on 2024/02/04 09:09
linux-6.6 INFO: task hung in netdev_run_todo (2) 1 1 74d 74d 0/2 upstream: reported on 2026/01/14 20:32
upstream INFO: task hung in netdev_run_todo (2) staging wireguard usb 1 C error 241 776d 1933d 0/29 auto-obsoleted due to no activity on 2024/05/05 22:51
android-49 INFO: task hung in netdev_run_todo 1 1 2900d 2900d 0/3 auto-closed as invalid on 2019/02/22 14:57
linux-4.14 INFO: task hung in netdev_run_todo 1 1 1233d 1233d 0/1 auto-obsoleted due to no activity on 2023/03/13 17:45
android-6-12 INFO: task hung in netdev_run_todo 1 184 136d 281d 0/1 auto-obsoleted due to no activity on 2026/01/03 01:56
linux-5.15 INFO: task hung in netdev_run_todo (2) 1 54 497d 679d 0/3 auto-obsoleted due to no activity on 2025/01/26 20:30
upstream INFO: task can't die in netdev_run_todo net 1 syz error 2 1655d 2048d 0/29 auto-obsoleted due to no activity on 2023/04/16 04:59

Sample crash report:
INFO: task kworker/0:4:373 blocked for more than 125 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:4     state:D stack:0     pid:373   tgid:373   ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6016 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7870
 __schedule_loop kernel/sched/core.c:7951 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7966
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8023
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 rcu_barrier+0x4d/0x540 kernel/rcu/tree.c:4589
 netdev_run_todo+0x118/0xce0 net/core/dev.c:10887
 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
 unregister_netdev+0x166/0x1d0 net/core/dev.c:11589
 usbnet_disconnect+0xd5/0x3a0 drivers/net/usb/usbnet.c:1653
 usb_unbind_interface+0x2aa/0xa30 drivers/usb/core/driver.c:462
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x4c2/0x790 drivers/base/dd.c:1295
 device_release_driver+0x1d/0x30 drivers/base/dd.c:1318
 bus_remove_device+0x359/0x380 drivers/base/bus.c:576
 device_del+0x581/0xd00 drivers/base/core.c:3881
 usb_disable_device+0x3af/0x770 drivers/usb/core/message.c:1418
 usb_disconnect+0x322/0x930 drivers/usb/core/hub.c:2353
 hub_port_connect drivers/usb/core/hub.c:5414 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5714 [inline]
 port_event drivers/usb/core/hub.c:5878 [inline]
 hub_event+0x1c7a/0x4700 drivers/usb/core/hub.c:5960
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d1/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 e5e4876e63e0994bd4350cd5f958f668e2098f7e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xdad/0xf00 kernel/hung_task.c:423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 33 Comm: rcuop/1 Not tainted syzkaller #0 e5e4876e63e0994bd4350cd5f958f668e2098f7e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:bcmp+0x22a/0x240 lib/string.c:704
Code: 89 7d c8 48 89 cf 49 89 d4 49 89 f6 41 89 c5 e8 7c af 42 fc 44 89 e8 48 8b 7d c8 4c 89 f6 4c 89 e2 eb 96 31 c0 48 83 c4 10 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 08 3b 06 00 cc 0f 1f 80 00 00 00 00
RSP: 0018:ffffc90000230550 EFLAGS: 00000286
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffc90000230608 RDI: ffff888106313018
RBP: ffffc90000230570 R08: 000000001baaaaaa R09: 1ffff920000460c0
R10: dffffc0000000000 R11: fffff520000460c1 R12: 00001baaaaaaaaaa
R13: 0000000000000000 R14: ffff888106313018 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6535345000 CR3: 0000000125b76000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 memcmp include/linux/fortify-string.h:715 [inline]
 rhashtable_compare include/linux/rhashtable.h:585 [inline]
 __rhashtable_lookup include/linux/rhashtable.h:610 [inline]
 rhashtable_lookup include/linux/rhashtable.h:646 [inline]
 fdb_find_rcu+0x2cb/0x540 net/bridge/br_fdb.c:223
 br_fdb_update+0x109/0x680 net/bridge/br_fdb.c:903
 br_handle_frame_finish+0x3a3/0x1760 net/bridge/br_input.c:141
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xfb1/0x3ab0 net/core/dev.c:5670
 __netif_receive_skb_one_core net/core/dev.c:5774 [inline]
 __netif_receive_skb net/core/dev.c:5889 [inline]
 process_backlog+0x3e5/0xad0 net/core/dev.c:6225
 __napi_poll+0xd0/0x610 net/core/dev.c:6876
 napi_poll net/core/dev.c:6945 [inline]
 net_rx_action+0x5ea/0xd80 net/core/dev.c:7067
 handle_softirqs+0x1ad/0x630 kernel/softirq.c:621
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xb8/0x110 kernel/softirq.c:503
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5d9/0xd40 kernel/rcu/tree.c:2594
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x524/0xb30 kernel/rcu/tree_nocb.h:957
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 110494 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:92:e2:38:7e:ad:41, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
net_ratelimit: 129988 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:92:e2:38:7e:ad:41, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)

Crashes (47):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/27 00:09 android16-6.12 d73a8ddf419e 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/24 20:22 android16-6.12 d671506859f7 74e70d19 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/20 00:33 android16-6.12 e34608848261 bd6dcb30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/17 19:56 android16-6.12 18ca40f8c454 c8810548 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/10 21:45 android16-6.12 752020e22de7 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/09 10:29 android16-6.12 f8e2ea1b4bbd 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/08 15:19 android16-6.12 f8e2ea1b4bbd 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/05 13:08 android16-6.12 6a6bc2e596fe d20b04c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/05 05:47 android16-6.12 f6f9e74eb0b6 a9fe5c9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/03 18:24 android16-6.12 c146faa1afa9 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/02 20:12 android16-6.12 a57a57875c30 b9dd6534 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/01 12:15 android16-6.12 7de305bfa436 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/03/01 02:28 android16-6.12 7de305bfa436 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/28 18:02 android16-6.12 7de305bfa436 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/28 01:35 android16-6.12 9791d9d4829d 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/26 18:02 android16-6.12 c69c5b7bed00 ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/26 02:55 android16-6.12 ce2208a17f48 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/23 19:50 android16-6.12 c42c886c1098 6beca497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/22 05:12 android16-6.12 7712ca595283 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/22 00:19 android16-6.12 7712ca595283 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/21 19:31 android16-6.12 7712ca595283 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/21 15:44 android16-6.12 7712ca595283 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/21 05:55 android16-6.12 7712ca595283 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/17 20:20 android16-6.12 381d050bce88 06ec4f7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/17 07:00 android16-6.12 f2758f0da7bc e439b951 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/16 03:28 android16-6.12 837ec018b485 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/15 10:59 android16-6.12 837ec018b485 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/15 10:42 android16-6.12 837ec018b485 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/15 04:03 android16-6.12 837ec018b485 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/13 20:29 android16-6.12 a18295bb2ff6 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/13 04:03 android16-6.12 7b84a1af9194 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/12 17:11 android16-6.12 8509f529f4f8 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/08 20:32 android16-6.12 6aeca23b5dee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/08 05:53 android16-6.12 6aeca23b5dee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/06 11:43 android16-6.12 356523087425 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/04 19:27 android16-6.12 e92d2e0f2328 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/02 20:28 android16-6.12 12691bc9c3f1 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/01 00:26 android16-6.12 c13babfee861 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/02/01 00:26 android16-6.12 c13babfee861 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/30 23:09 android16-6.12 c13babfee861 ae7dc18c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/30 23:09 android16-6.12 c13babfee861 ae7dc18c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/30 02:54 android16-6.12 d60ccb82b419 bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/29 17:44 android16-6.12 6acc5550e55c aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/28 01:23 android16-6.12 1c8fffa12a81 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/27 10:06 android16-6.12 0a08bd027b15 efb3e894 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/26 12:19 android16-6.12 132542afc0ef a4c52dd6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2026/01/22 03:01 android16-6.12 f33ca06267f8 8fc37797 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
* Struck through repros no longer work on HEAD.