syzbot

INFO: task syz-executor:9058 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:9058  tgid:9058  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4589
 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10880
 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:429
 ____fput+0x20/0x30 fs/file_table.c:457
 task_work_run+0x1e0/0x250 kernel/task_work.c:240
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9bc/0x2630 kernel/exit.c:953
 do_group_exit+0x22a/0x300 kernel/exit.c:1095
 get_signal+0x139d/0x14f0 kernel/signal.c:2933
 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: 0033:0x7efc5e191503
RSP: 002b:00007ffea1494bc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 0000000000000064 RBX: 00007efc5ef14620 RCX: 00007efc5e191503
RDX: 0000000000000064 RSI: 00007efc5ef14670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffea1494be4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007efc5ef14670 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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:267 [inline]
 watchdog+0xd8f/0xed0 kernel/hung_task.c:423
 kthread+0x2ca/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 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 70 05 48 89 de e8 10 5f 52 00 5b 5d e9 c9 bc 09 04 cc cc cc cc cc cc cc cc cc b8 fc fe 0a 69 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 48 89 e5 48 8b 45 08 65 48 8b 0c 25 00 eb 04 00 65
RSP: 0018:ffffc900002302d8 EFLAGS: 00000246
RAX: 0000000000080000 RBX: 0000000000000000 RCX: 0000000000000100
RDX: ffff88810367a600 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900002304d8 R08: ffff888101353000 R09: 0000000000000000
R10: ffffc90000230430 R11: fffff5200004608a R12: ffff8881013530f0
R13: dffffc0000000000 R14: ffff888101353040 R15: 00000000000000a8
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcdc3550235 CR3: 00000001223f2000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 nf_hook_entry_hookfn include/linux/netfilter.h:155 [inline]
 nf_hook_slow+0xd2/0x240 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:272 [inline]
 NF_HOOK include/linux/netfilter.h:315 [inline]
 ipv6_rcv+0x1c7/0x220 net/ipv6/ip6_input.c:309
 __netif_receive_skb_one_core net/core/dev.c:5769 [inline]
 __netif_receive_skb net/core/dev.c:5882 [inline]
 netif_receive_skb_internal net/core/dev.c:5968 [inline]
 netif_receive_skb+0x147/0x7b0 net/core/dev.c:6027
 br_netif_receive_skb net/bridge/br_input.c:30 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_pass_frame_up+0x126/0x1c0 net/bridge/br_input.c:70
 br_handle_frame_finish+0x12d9/0x1720 net/bridge/br_input.c:221
 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+0xf4b/0x3940 net/core/dev.c:5663
 __netif_receive_skb_one_core net/core/dev.c:5767 [inline]
 __netif_receive_skb net/core/dev.c:5882 [inline]
 process_backlog+0x3e5/0xae0 net/core/dev.c:6218
 __napi_poll+0xd3/0x610 net/core/dev.c:6869
 napi_poll net/core/dev.c:6938 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7060
 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xa6/0x100 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+0x5c6/0xd20 kernel/rcu/tree.c:2594
 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+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 156297 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:86:89:66:cd:98:a5, vlan:0)
net_ratelimit: 182350 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:86:89:66:cd:98:a5, 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:00:00:00:00:67:5f, 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:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:06:48:7f:51:d3:73, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)