INFO: task kworker/0:1:10 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:1 state:D stack:0 pid:10 tgid:10 ppid:2 flags:0x00004000 Workqueue: events fqdir_free_fn 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 fqdir_free_fn+0x36/0x150 net/ipv4/inet_fragment.c:167 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2c7/0x370 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 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 ecd017b10525a6fce0a0b730885af6e9bd831db9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0x2c7/0x370 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 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 ecd017b10525a6fce0a0b730885af6e9bd831db9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:unwind_next_frame+0x0/0x750 arch/x86/kernel/unwind_frame.c:265 Code: cc cc 89 d9 80 e1 07 80 c1 03 38 c1 7c 96 48 89 df e8 a4 ee 97 00 eb 8c 66 90 b8 46 e7 45 5a 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 48 48 RSP: 0018:ffffc900002303e0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc900002304a0 RCX: 0000000000230400 RDX: dffffc0000000000 RSI: ffffffff8157da27 RDI: ffffc900002303e8 RBP: ffffc90000230470 R08: ffffc900002304b0 R09: ffffc900002304a8 R10: 0000000000000015 R11: ffffffff81744330 R12: ffff88810367b900 R13: 1ffff1102f878067 R14: ffffffff81744330 R15: ffffc900002303e8 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f00bf2f7d60 CR3: 000000010bf14000 CR4: 00000000003526b0 Call Trace: 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+0x154/0x1b0 include/linux/netfilter.h:317 arp_rcv+0x2f8/0x490 net/ipv4/arp.c:991 __netif_receive_skb_one_core net/core/dev.c:5757 [inline] __netif_receive_skb net/core/dev.c:5870 [inline] process_backlog+0x553/0xae0 net/core/dev.c:6206 __napi_poll+0xd3/0x610 net/core/dev.c:6857 napi_poll net/core/dev.c:6926 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7048 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+0x2c7/0x370 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 net_ratelimit: 114348 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 veth0_to_bridge with own address as source address (addr:1a:fc:b0:b7:da:75, 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 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:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:1a:fc:b0:b7:da:75, vlan:0)