INFO: task syz.6.7947:23896 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.7947      state:D stack:0     pid:23896 tgid:23895 ppid:18238  flags:0x00004004
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
 flush_rcu_work+0x71/0x90 kernel/workqueue.c:4292
 kvfree_rcu_barrier+0x23c/0x2f0 kernel/rcu/tree.c:3955
 kmem_cache_destroy+0x32/0x170 mm/slab_common.c:490
 p9_client_destroy+0x42b/0x480 net/9p/client.c:1088
 v9fs_session_close+0x52/0x1d0 fs/9p/v9fs.c:506
 v9fs_kill_super+0x60/0x90 fs/9p/vfs_super.c:196
 deactivate_locked_super+0xd5/0x2a0 fs/super.c:476
 deactivate_super+0xb8/0xe0 fs/super.c:509
 cleanup_mnt+0x3f1/0x480 fs/namespace.c:1370
 __cleanup_mnt+0x1d/0x40 fs/namespace.c:1377
 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: 0033:0x7f331f78efc9
RSP: 002b:00007f33205f8038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffe RBX: 00007f331f9e5fa0 RCX: 00007f331f78efc9
RDX: 0000200000004380 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f331f811f91 R08: 0000200000000280 R09: 0000000000000000
R10: 0000000001814800 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f331f9e6038 R14: 00007f331f9e5fa0 R15: 00007fff5d3288f8
 </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: 20 Comm: rcuop/0 Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__kmalloc_cache_noprof+0x10/0x490 mm/slub.c:4396
Code: 84 00 00 00 00 00 0f 1f 40 00 b8 4e 16 69 81 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 <53> 48 83 ec 40 49 89 d6 41 89 f7 49 89 fc 65 48 8b 04 25 28 00 00
RSP: 0018:ffffc9000022fef0 EFLAGS: 00000246
RAX: 1ffffffff0dedaab RBX: dffffc0000000000 RCX: ffff888103661300
RDX: 0000000000000020 RSI: 0000000000002920 RDI: ffff888100041780
RBP: ffffc9000022ff10 R08: ffffc9000022ffdf R09: 0000000000000000
R10: ffffc9000022ff60 R11: fffff52000045ffc R12: ffff888148645368
R13: 0000000000002920 R14: 0000000000000820 R15: ffffffff86f6d558
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f996e3ae4c0 CR3: 000000010bb1a000 CR4: 00000000003526b0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 kmalloc_noprof include/linux/slab.h:881 [inline]
 kzalloc_noprof include/linux/slab.h:1017 [inline]
 ref_tracker_alloc+0x153/0x540 lib/ref_tracker.c:203
 __netdev_tracker_alloc include/linux/netdevice.h:4109 [inline]
 netdev_hold include/linux/netdevice.h:4138 [inline]
 dst_init+0xcf/0x420 net/core/dst.c:52
 dst_alloc+0x163/0x250 net/core/dst.c:93
 rt_dst_alloc net/ipv4/route.c:1642 [inline]
 ip_route_input_slow net/ipv4/route.c:2380 [inline]
 ip_route_input_rcu+0x184a/0x2520 net/ipv4/route.c:2494
 ip_route_input_noref+0xbf/0x130 net/ipv4/route.c:2505
 arp_process+0x89d/0x1740 net/ipv4/arp.c:840
 NF_HOOK+0x157/0x1b0 include/linux/netfilter.h:317
 arp_rcv+0x2f8/0x490 net/ipv4/arp.c:991
 __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+0x22a/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: 63347 callbacks suppressed
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: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)
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:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:6a:f1:24:ce:78, 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 veth0_to_bridge 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)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:2e:6a:f1:24:ce:78, vlan:0)
net_ratelimit: 74085 callbacks suppressed
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:2e:6a:f1:24:ce:78, 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)
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 veth0_to_bridge with own address as source address (addr:2e:6a:f1:24:ce:78, 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 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:0c, vlan:0)