INFO: task syz.4.3562:10821 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3562 state:D stack:0 pid:10821 tgid:10820 ppid:7474 flags:0x00004004 Call Trace: 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_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:4657 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: 0033:0x7f607cf8efc9 RSP: 002b:00007f607dea8038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: fffffffffffffffe RBX: 00007f607d1e5fa0 RCX: 00007f607cf8efc9 RDX: 0000200000004380 RSI: 0000200000000180 RDI: 0000000000000000 RBP: 00007f607d011f91 R08: 0000200000000080 R09: 0000000000000000 R10: 0000000000000080 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f607d1e6038 R14: 00007f607d1e5fa0 R15: 00007ffec5f39948 NMI backtrace for cpu 1 CPU: 1 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: __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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 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:unwind_get_return_address+0x49/0x90 arch/x86/kernel/unwind_frame.c:19 Code: e8 03 42 0f b6 04 30 84 c0 75 4d 83 3b 00 74 3a 48 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 e7 3f 98 00 <48> 8b 3b e8 ff 14 13 00 85 c0 74 14 43 80 3c 37 00 74 08 48 89 df RSP: 0018:ffffc900000073c0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90000007430 RCX: 0000000000007401 RDX: ffffc90000007d30 RSI: 1ffff92000000e7e RDI: ffffc900000073e8 RBP: ffffc900000073d8 R08: ffffc900000074b0 R09: ffffc900000074a8 R10: 000000000000000d R11: ffffffff817457d0 R12: ffff888103661300 R13: 1ffff1102e972847 R14: dffffc0000000000 R15: 1ffff92000000e86 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbfe5f17d60 CR3: 000000018d6a0000 CR4: 00000000003526b0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x10b/0x170 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:48 __kasan_record_aux_stack+0xb2/0xd0 mm/kasan/generic.c:541 kasan_record_aux_stack_noalloc+0xf/0x20 mm/kasan/generic.c:551 __call_rcu_common+0xd5/0x700 kernel/rcu/tree.c:3098 call_rcu_hurry+0xf/0x30 kernel/rcu/tree.c:3149 dst_release+0x1a3/0x240 net/core/dst.c:177 refdst_drop include/net/dst.h:263 [inline] skb_dst_drop include/net/dst.h:275 [inline] skb_release_head_state+0x74/0x260 net/core/skbuff.c:1172 skb_release_all net/core/skbuff.c:1186 [inline] __kfree_skb+0x29/0x210 net/core/skbuff.c:1202 consume_skb+0x65/0x1a0 net/core/skbuff.c:1434 arp_process+0xd79/0x1740 net/ipv4/arp.c:941 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] process_backlog+0x556/0xae0 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 __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 net_ratelimit: 120799 callbacks suppressed 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: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: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 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)