INFO: task syz-executor:4530 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:4530 tgid:4530 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:6027 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7894 __schedule_loop kernel/sched/core.c:7975 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7990 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8047 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rtnl_lock net/core/rtnetlink.c:79 [inline] rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6675 netlink_rcv_skb+0x259/0x4f0 net/netlink/af_netlink.c:2545 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x68d/0x700 net/socket.c:2216 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xe9/0x100 net/socket.c:2224 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f486a357fd7 RSP: 002b:00007ffedd2fddc0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055558cf91500 RCX: 00007f486a357fd7 RDX: 0000000000000028 RSI: 00007f486b144670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffedd2fde24 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f486b144670 R15: 0000000000000000 INFO: task syz-executor:4532 blocked for more than 129 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:4532 tgid:4532 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:6027 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7894 __schedule_loop kernel/sched/core.c:7975 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7990 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8047 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rtnl_lock net/core/rtnetlink.c:79 [inline] rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6675 netlink_rcv_skb+0x259/0x4f0 net/netlink/af_netlink.c:2545 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x68d/0x700 net/socket.c:2216 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xe9/0x100 net/socket.c:2224 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fbbe6b57fd7 RSP: 002b:00007ffe2f8c84f0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055557f1fd500 RCX: 00007fbbe6b57fd7 RDX: 0000000000000028 RSI: 00007fbbe7944670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffe2f8c8554 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fbbe7944670 R15: 0000000000000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 cd47f8e0083a5f781c340422d7a309d6c8dfd054 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0xdad/0xf00 kernel/hung_task.c:423 kthread+0x2c9/0x370 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: 883 Comm: kworker/0:5 Not tainted syzkaller #0 cd47f8e0083a5f781c340422d7a309d6c8dfd054 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: mld mld_query_work RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_switch+0xab/0x130 kernel/kcov.c:351 Code: c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d 3f 1d 7d 7e 41 81 e3 00 01 ff 00 74 13 41 81 fb 00 01 00 00 75 d9 <41> 83 b8 ec 0b 00 00 00 74 cf 45 8b 98 c8 0b 00 00 41 83 fb 03 75 RSP: 0018:ffffc90000006b08 EFLAGS: 00000246 RAX: 0000000000000008 RBX: ffff8881186ec080 RCX: 0000000000000001 RDX: ffffffff84ee3c8b RSI: ffffffff87d48a90 RDI: 000000000000003a RBP: ffffc90000006b28 R08: ffff88812013cc00 R09: 0000000000000002 R10: 0000000000000011 R11: 0000000000000100 R12: ffffc90000006fb0 R13: ffff8881186ec0a2 R14: 0000000000000000 R15: 000000000000003a FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa4cd615f40 CR3: 000000010cf10000 CR4: 00000000003526b0 Call Trace: xfrm_flowi_sport include/net/xfrm.h:917 [inline] __xfrm6_selector_match net/xfrm/xfrm_policy.c:237 [inline] xfrm_selector_match+0x66b/0x1100 net/xfrm/xfrm_policy.c:249 xfrm_policy_match net/xfrm/xfrm_policy.c:1984 [inline] xfrm_policy_lookup_bytype+0x86a/0x1500 net/xfrm/xfrm_policy.c:2183 xfrm_policy_lookup net/xfrm/xfrm_policy.c:2236 [inline] __xfrm_policy_check+0xb5b/0x3540 net/xfrm/xfrm_policy.c:3742 __xfrm_policy_check2+0x36a/0x720 include/net/xfrm.h:1242 xfrm_policy_check include/net/xfrm.h:1247 [inline] xfrm6_policy_check include/net/xfrm.h:1257 [inline] icmpv6_rcv+0x10e/0x1790 net/ipv6/icmp.c:917 ip6_protocol_deliver_rcu+0xbc5/0x12f0 net/ipv6/ip6_input.c:436 ip6_input_finish net/ipv6/ip6_input.c:481 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] ip6_input+0x1cd/0x3a0 net/ipv6/ip6_input.c:490 ip6_mc_input+0x35a/0x6c0 net/ipv6/ip6_input.c:584 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish+0x344/0x3c0 net/ipv6/ip6_input.c:79 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+0x147/0x7b0 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+0x120c/0x17a0 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+0xfae/0x3ab0 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+0x3e5/0xad0 net/core/dev.c:6250 __napi_poll+0xd3/0x610 net/core/dev.c:6901 napi_poll net/core/dev.c:6970 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7092 handle_softirqs+0x1aa/0x630 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 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x54/0x60 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] mld_query_work+0x984/0x2c50 net/ipv6/mcast.c:1528 process_one_work kernel/workqueue.c:3261 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423 kthread+0x2c9/0x370 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