syzbot


INFO: task hung in netdev_run_todo

Status: premoderation: reported on 2025/06/22 07:19
Reported-by: syzbot+1233d01ce7a389688b0c@syzkaller.appspotmail.com
First crash: 2d13h, last: 6h33m
Similar bugs (13)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in netdev_run_todo (3) 15 960d 1276d 0/1 auto-obsoleted due to no activity on 2023/03/07 08:19
upstream INFO: task hung in netdev_run_todo net 12 2134d 2689d 0/29 closed as invalid on 2019/10/23 07:29
linux-4.19 INFO: task hung in netdev_run_todo (2) 3 1767d 1815d 0/1 auto-closed as invalid on 2020/12/20 04:57
android-44 INFO: task hung in netdev_run_todo 1 2628d 2628d 0/2 auto-closed as invalid on 2019/02/22 12:49
upstream INFO: task hung in netdev_run_todo (4) wireguard 342 40m 258d 0/29 upstream: reported on 2024/10/09 19:06
linux-4.19 INFO: task hung in netdev_run_todo 1 2093d 2093d 0/1 auto-closed as invalid on 2020/01/29 06:48
upstream INFO: task hung in netdev_run_todo (3) net 24 371d 409d 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 606d 606d 0/3 auto-obsoleted due to no activity on 2024/02/04 09:09
upstream INFO: task hung in netdev_run_todo (2) staging wireguard usb C error 241 497d 1654d 0/29 auto-obsoleted due to no activity on 2024/05/05 22:51
android-49 INFO: task hung in netdev_run_todo 1 2621d 2621d 0/3 auto-closed as invalid on 2019/02/22 14:57
linux-4.14 INFO: task hung in netdev_run_todo 1 954d 954d 0/1 auto-obsoleted due to no activity on 2023/03/13 17:45
linux-5.15 INFO: task hung in netdev_run_todo (2) 54 219d 400d 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 syz error 2 1376d 1769d 0/29 auto-obsoleted due to no activity on 2023/04/16 04:59

Sample crash report:
INFO: task syz-executor:7672 blocked for more than 123 seconds.
      Not tainted 6.12.30-syzkaller-g9d80e3254812 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:7672  tgid:7672  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270
 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4574
 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10864
 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0xc5/0x150 drivers/net/tun.c:3517
 __fput+0x1fb/0xa00 fs/file_table.c:431
 ____fput+0x20/0x30 fs/file_table.c:459
 task_work_run+0x1e0/0x250 kernel/task_work.c:240
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9b4/0x2630 kernel/exit.c:944
 do_group_exit+0x22a/0x300 kernel/exit.c:1094
 get_signal+0x139d/0x14f0 kernel/signal.c:2934
 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f5b47984b53
RSP: 002b:00007ffddc9bfd88 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000000000000007 RCX: 00007f5b47984b53
RDX: 0000000040000000 RSI: 00007ffddc9bfdcc RDI: 00000000ffffffff
RBP: 00007ffddc9bfdcc R08: 000000003b535049 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000001
R13: 00005555660ed470 R14: 0000000000036e50 R15: 00007ffddc9bfe20
 </TASK>
INFO: task syz.2.2574:7749 blocked for more than 127 seconds.
      Not tainted 6.12.30-syzkaller-g9d80e3254812 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2574      state:D stack:0     pid:7749  tgid:7749  ppid:7672   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x359/0x630 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4642
 kvm_mmu_uninit_tdp_mmu+0x1df/0x210 arch/x86/kvm/mmu/tdp_mmu.c:51
 kvm_mmu_uninit_vm+0x27/0x60 arch/x86/kvm/mmu/mmu.c:6572
 kvm_arch_destroy_vm+0x383/0x410 arch/x86/kvm/x86.c:12898
 kvm_destroy_vm virt/kvm/kvm_main.c:1355 [inline]
 kvm_put_kvm+0xb04/0x12b0 virt/kvm/kvm_main.c:1391
 kvm_vm_release+0x47/0x70 virt/kvm/kvm_main.c:1414
 __fput+0x1fb/0xa00 fs/file_table.c:431
 ____fput+0x20/0x30 fs/file_table.c:459
 task_work_run+0x1e0/0x250 kernel/task_work.c:240
 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x64/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f5b4798e929
RSP: 002b:00007ffddc9bfb68 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000036c8d RCX: 00007f5b4798e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f5b47bb7ba0 R08: 0000000000000001 R09: 00000012dc9bfe5f
R10: 00007f5b47800000 R11: 0000000000000246 R12: 00007f5b47bb5fac
R13: 00007f5b47bb5fa0 R14: ffffffffffffffff R15: 00007ffddc9bfc80
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.30-syzkaller-g9d80e3254812 #0 0af3bb1b2b1f0d17039a87b1bb907b41f79d5270
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2bf/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:229 [inline]
 watchdog+0xd8f/0xed0 kernel/hung_task.c:385
 kthread+0x2ca/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 20 Comm: rcuop/0 Not tainted 6.12.30-syzkaller-g9d80e3254812 #0 0af3bb1b2b1f0d17039a87b1bb907b41f79d5270
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x33/0x70 kernel/kcov.c:217
Code: 8b 45 08 65 48 8b 0c 25 40 e9 04 00 65 8b 15 7c 48 7f 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 ec 0b 00 00 00 <74> 2c 8b 91 c8 0b 00 00 83 fa 02 75 21 48 8b 91 d0 0b 00 00 48 8b
RSP: 0018:ffffc900000071e8 EFLAGS: 00000246
RAX: ffffffff84e09899 RBX: ffff888138248cc0 RCX: ffff888103662600
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888138248cc0
RBP: ffffc900000071e8 R08: ffffc90000007540 R09: ffffc90000007550
R10: ffffc900000076b0 R11: fffff52000000eda R12: 0000000000000001
R13: ffffc90000007540 R14: 0000000000000003 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffbcfe3fff8 CR3: 0000000107ab6000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 find_match+0x39/0x10f0 net/ipv6/route.c:773
 __find_rr_leaf+0x23c/0x790 net/ipv6/route.c:869
 find_rr_leaf net/ipv6/route.c:890 [inline]
 rt6_select net/ipv6/route.c:934 [inline]
 fib6_table_lookup+0x2c5/0x9b0 net/ipv6/route.c:2230
 ip6_pol_route+0x167/0x12c0 net/ipv6/route.c:2266
 ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2323
 pol_lookup_func include/net/ip6_fib.h:626 [inline]
 fib6_rule_lookup+0x4cc/0x6b0 net/ipv6/fib6_rules.c:117
 ip6_route_input_lookup net/ipv6/route.c:2335 [inline]
 ip6_route_input+0x59f/0x8d0 net/ipv6/route.c:2631
 ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline]
 ip6_rcv_finish+0x15a/0x3c0 net/ipv6/ip6_input.c:77
 NF_HOOK include/linux/netfilter.h:317 [inline]
 ipv6_rcv+0xed/0x220 net/ipv6/ip6_input.c:309
 __netif_receive_skb_one_core net/core/dev.c:5757 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 process_backlog+0x44b/0xae0 net/core/dev.c:6202
 __napi_poll+0xd3/0x610 net/core/dev.c:6853
 napi_poll net/core/dev.c:6922 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7044
 handle_softirqs+0x1ae/0x630 kernel/softirq.c:603
 __do_softirq+0xf/0x16 kernel/softirq.c:641
 do_softirq+0xa6/0x100 kernel/softirq.c:485
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:412
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2586
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957
 kthread+0x2ca/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 47300 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:9e:75:0f:59:51:68, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:9e:75:0f:59:51:68, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:9e:75:0f:59:51:68, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/24 14:21 android16-6.12 9d80e3254812 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2025/06/24 11:53 android16-6.12 9d80e3254812 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2025/06/23 14:25 android16-6.12 5bf4b91e3333 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2025/06/23 13:49 android16-6.12 5bf4b91e3333 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2025/06/23 13:22 android16-6.12 5bf4b91e3333 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2025/06/23 12:54 android16-6.12 5bf4b91e3333 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2025/06/22 13:21 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in netdev_run_todo
2025/06/22 07:18 android16-6.12 d9fd901baa98 d6cdfb8a .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.