INFO: task kworker/0:4:319 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:0 pid:319 tgid:319 ppid:2 flags:0x00004000 Workqueue: events fqdir_free_fn Call Trace: context_switch kernel/sched/core.c:6052 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7865 __schedule_loop kernel/sched/core.c:7942 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7957 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x368/0x650 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x45a/0x580 kernel/rcu/tree.c:4657 fqdir_free_fn+0x36/0x150 net/ipv4/inet_fragment.c:167 process_one_work kernel/workqueue.c:3273 [inline] process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354 worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435 kthread+0x2c7/0x360 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 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 991092e6aacd45c89fe3e25b50ff7d10cec51463 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2ba/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+0xe45/0xf90 kernel/hung_task.c:423 kthread+0x2c7/0x360 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 20 Comm: rcuop/0 Not tainted syzkaller #0 991092e6aacd45c89fe3e25b50ff7d10cec51463 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x88/0x2b0 mm/kasan/generic.c:189 Code: 01 00 00 00 00 fc ff df 4d 8d 34 19 4d 89 f5 4d 29 dd 49 83 fd 10 7f 29 4d 85 ed 0f 84 46 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb <41> 80 3b 00 0f 85 9f 01 00 00 49 ff c3 48 ff c3 75 ee e9 26 01 00 RSP: 0018:ffffc900002302e0 EFLAGS: 00000286 RAX: ffff88812ca33501 RBX: fffffffffffffffc RCX: ffffffff84fa3af0 RDX: 0000000000000001 RSI: 0000000000000028 RDI: ffffc900002303a0 RBP: ffffc90000230308 R08: ffffc900002303c7 R09: 1ffff92000046078 R10: dffffc0000000000 R11: fffff52000046075 R12: ffff888127955180 R13: 0000000000000005 R14: fffff52000046079 R15: 1ffff92000046074 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8b6f586fc0 CR3: 0000000116c80000 CR4: 00000000003526b0 Call Trace: __asan_memset+0x27/0x50 mm/kasan/shadow.c:84 ip6_route_input+0x170/0x8d0 net/ipv6/route.c:2623 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+0xf1/0x240 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core net/core/dev.c:5801 [inline] __netif_receive_skb net/core/dev.c:5914 [inline] netif_receive_skb_internal net/core/dev.c:6000 [inline] netif_receive_skb+0x146/0x7b0 net/core/dev.c:6059 br_netif_receive_skb net/bridge/br_input.c:30 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] br_pass_frame_up+0x126/0x1b0 net/bridge/br_input.c:70 br_handle_frame_finish+0x1178/0x1620 net/bridge/br_input.c:-1 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline] br_handle_frame+0x5a5/0xba0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xfc1/0x3a70 net/core/dev.c:5695 __netif_receive_skb_one_core net/core/dev.c:5799 [inline] __netif_receive_skb net/core/dev.c:5914 [inline] process_backlog+0x40b/0xaf0 net/core/dev.c:6250 __napi_poll+0xd0/0x600 net/core/dev.c:6901 napi_poll net/core/dev.c:6970 [inline] net_rx_action+0x5dc/0xd70 net/core/dev.c:7092 handle_softirqs+0x1aa/0x620 kernel/softirq.c:621 __do_softirq+0xf/0x16 kernel/softirq.c:659 do_softirq+0xb8/0x110 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+0x590/0xcb0 kernel/rcu/tree.c:2594 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline] rcu_nocb_cb_kthread+0x533/0xb60 kernel/rcu/tree_nocb.h:957 kthread+0x2c7/0x360 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: 159446 callbacks suppressed ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0! ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0! ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0! ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! net_ratelimit: 184641 callbacks suppressed ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0! ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0! ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge! bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge!