INFO: task syz.0.2691:15819 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2691 state:D stack:26648 pid:15819 tgid:15815 ppid:5607 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7322
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_work+0x7c7/0xcb0 kernel/workqueue.c:4374
p9_mux_poll_stop net/9p/trans_fd.c:140 [inline]
p9_conn_destroy net/9p/trans_fd.c:804 [inline]
p9_fd_close+0x299/0x5a0 net/9p/trans_fd.c:840
p9_client_create+0x678/0xd40 net/9p/client.c:937
v9fs_session_init+0x3c/0xd20 fs/9p/v9fs.c:446
v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
vfs_get_tree+0x92/0x320 fs/super.c:1694
fc_mount fs/namespace.c:1198 [inline]
do_new_mount_fc fs/namespace.c:3765 [inline]
do_new_mount fs/namespace.c:3841 [inline]
path_mount+0x7d0/0x23d0 fs/namespace.c:4161
do_mount fs/namespace.c:4174 [inline]
__do_sys_mount fs/namespace.c:4390 [inline]
__se_sys_mount fs/namespace.c:4367 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4367
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7ef499ce59
RSP: 002b:00007f7ef5818028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f7ef4c16090 RCX: 00007f7ef499ce59
RDX: 0000200000000040 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007f7ef4a32d6f R08: 0000200000000300 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7ef4c16128 R14: 00007f7ef4c16090 R15: 00007ffc87e03f38
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14683 Comm: kworker/1:0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: mld mld_dad_work
RIP: 0010:__in6_dev_get include/net/addrconf.h:348 [inline]
RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:452 [inline]
RIP: 0010:find_match net/ipv6/route.c:783 [inline]
RIP: 0010:__find_rr_leaf+0x186/0x1040 net/ipv6/route.c:872
Code: 0d 00 00 4c 8b bb c8 00 00 00 49 8d bf c0 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 c1 0d 00 00 4d 8b bf c0 00 00 00 c5 99 50 01 31 ff 89 c6 89 44 24 38 e8 b8 62 c6 f7 8b 44 24 38
RSP: 0018:ffffc90000a084a8 EFLAGS: 00000246
RAX: 1ffff110044fc018 RBX: ffff8880760b3400 RCX: ffffffff8a4307f6
RDX: ffff88802e348000 RSI: ffffffff8a430804 RDI: ffff8880227e00c0
RBP: ffff8880760b3464 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffffc90000a08ff8 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff8880760b34df R15: ffff888078943000
FS: 0000000000000000(0000) GS:ffff888124432000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f9d8ff8 CR3: 000000002e50f000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f7 DR2: 00000000ffffffff
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
find_rr_leaf net/ipv6/route.c:893 [inline]
rt6_select net/ipv6/route.c:937 [inline]
fib6_table_lookup+0x50f/0xa10 net/ipv6/route.c:2255
ip6_pol_route+0x1d5/0x1310 net/ipv6/route.c:2292
pol_lookup_func include/net/ip6_fib.h:667 [inline]
fib6_rule_lookup+0x52f/0x720 net/ipv6/fib6_rules.c:123
ip6_route_input_lookup net/ipv6/route.c:2363 [inline]
ip6_route_input+0x662/0xc50 net/ipv6/route.c:2666
ip6_rcv_finish_core.isra.0+0x1b1/0x1260 net/ipv6/ip6_input.c:106
ip6_rcv_finish net/ipv6/ip6_input.c:117 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ipv6_rcv+0x1e8/0x3d0 net/ipv6/ip6_input.c:351
__netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6206
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6319
process_backlog+0x37a/0x1580 net/core/dev.c:6670
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7729
napi_poll net/core/dev.c:7792 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7949
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:914 [inline]
__dev_queue_xmit+0xa05/0x4940 net/core/dev.c:4907
dev_queue_xmit include/linux/netdevice.h:3436 [inline]
neigh_hh_output include/net/neighbour.h:544 [inline]
neigh_output include/net/neighbour.h:558 [inline]
ip6_finish_output2+0xfd4/0x1ce0 net/ipv6/ip6_output.c:136
__ip6_finish_output+0x357/0xdf0 net/ipv6/ip6_output.c:208
ip6_finish_output net/ipv6/ip6_output.c:219 [inline]
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x2aa/0xa60 net/ipv6/ip6_output.c:246
dst_output include/net/dst.h:470 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK.constprop.0+0x115/0x5a0 include/linux/netfilter.h:312
mld_sendpack+0x8f7/0xec0 net/ipv6/mcast.c:1853
mld_send_initial_cr+0x219/0x320 net/ipv6/mcast.c:2271
mld_dad_work+0x32/0x1f0 net/ipv6/mcast.c:2294
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245