INFO: task syz.3.11393:10825 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.11393 state:D stack:27168 pid:10825 tgid:10818 ppid:7684 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1798
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2555
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f690799ce59
RSP: 002b:00007f69087b0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6907c16180 RCX: 00007f690799ce59
RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000009
RBP: 00007f6907a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6907c16218 R14: 00007f6907c16180 R15: 00007ffd85a4dbb8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/47:
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90000b77c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90000b77c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
2 locks held by getty/5388:
#0: ffff888035fb70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:30/26837:
2 locks held by syz.8.11280/10451:
#0: ffffffff8fe377c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8b180 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
2 locks held by syz.3.11393/10825:
#0: ffffffff8fe377c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8b180 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1798
2 locks held by syz.4.12337/14095:
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3441
#1: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
2 locks held by syz.6.12342/14117:
#0: ffffffff903218e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff903218e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff903218e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
1 lock held by syz.6.12342/14120:
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3441
2 locks held by syz.7.12343/14119:
#0: ffffffff8fda8c00 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x641/0x7f0 net/socket.c:1396
#1: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xf0/0x630 net/8021q/vlan.c:579
1 lock held by syz.7.12343/14121:
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_setlink+0x55e/0x940 net/core/rtnetlink.c:3486
1 lock held by syz.7.12343/14124:
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:815
1 lock held by syz.9.12345/14132:
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3083
1 lock held by syz.9.12345/14133:
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3083
1 lock held by syz.9.12345/14134:
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 4999 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:trace_fib6_table_lookup+0x91/0x1f0 include/trace/events/fib6.h:13
Code: 40 0f 92 c6 bf 02 00 00 00 e8 0b dd 70 f7 84 db 74 10 e8 52 f0 55 f7 84 c0 74 27 e8 f9 d9 70 f7 eb 05 e8 f2 d9 70 f7 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 dd d9 70 f7 90 0f 0b 90
RSP: 0018:ffffc90000a08138 EFLAGS: 00000246
RAX: ffffffff8a54dca7 RBX: ffff8880568f6800 RCX: ffff88807e5a8000
RDX: 0000000000000100 RSI: ffffffff8c28b6c0 RDI: ffffffff8c28b680
RBP: ffffc90000a082d0 R08: ffffffff903024f7 R09: 1ffffffff206049e
R10: dffffc0000000000 R11: fffffbfff206049f R12: dffffc0000000000
R13: ffffc90000a08350 R14: 0000000000000001 R15: ffffc90000a08350
FS: 00007fce15957880(0000) GS:ffff88812539e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557ba724e8 CR3: 000000007e034000 CR4: 00000000003526f0
Call Trace:
fib6_table_lookup+0xa32/0xa80 net/ipv6/route.c:2267
ip6_pol_route+0x228/0x13d0 net/ipv6/route.c:2290
pol_lookup_func include/net/ip6_fib.h:667 [inline]
__fib6_rule_action net/ipv6/fib6_rules.c:240 [inline]
fib6_rule_action+0x265/0xc00 net/ipv6/fib6_rules.c:278
fib_rules_lookup+0x768/0xea0 net/core/fib_rules.c:339
fib6_rule_lookup+0x1a0/0x730 net/ipv6/fib6_rules.c:115
ip6_route_output_flags_noref net/ipv6/route.c:2706 [inline]
ip6_route_output_flags+0x364/0x5d0 net/ipv6/route.c:2718
ip6_route_output include/net/ip6_route.h:100 [inline]
icmpv6_xrlim_allow+0xb9/0x5f0 net/ipv6/icmp.c:211
icmp6_send+0x1023/0x1b50 net/ipv6/icmp.c:776
icmpv6_send include/linux/icmpv6.h:24 [inline]
ip6_link_failure+0x3b/0x4c0 net/ipv6/route.c:2865
dst_link_failure include/net/dst.h:438 [inline]
ndisc_error_report+0x118/0x160 net/ipv6/ndisc.c:733
neigh_invalidate+0x235/0x460 net/core/neighbour.c:1080
neigh_timer_handler+0xb99/0x11b0 net/core/neighbour.c:1172
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 a1 8f 05 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0b 7a 96 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 18 dd 91
RSP: 0018:ffffc90003baf7b8 EFLAGS: 00000286
RAX: 35c32574f0d26b00 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 000000003a0764ea RSI: ffffffff8e215f4f RDI: ffffffff8c28b6e0
RBP: ffffffff8176e256 R08: ffffffff8176e256 R09: ffffffff8e95cca0
R10: ffffc90003baf918 R11: ffffffff81b0e0e0 R12: 0000000000000002
R13: ffffffff8e95cca0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3131 [inline]
call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
__dentry_kill+0x4a9/0x690 fs/dcache.c:737
finish_dput+0xc9/0x480 fs/dcache.c:927
lookup_one_qstr_excl+0x1ca/0x360 fs/namei.c:-1
__start_dirop fs/namei.c:2916 [inline]
start_dirop fs/namei.c:2938 [inline]
filename_unlinkat+0x2ba/0x610 fs/namei.c:5549
__do_sys_unlink fs/namei.c:5603 [inline]
__se_sys_unlink+0x2e/0x140 fs/namei.c:5600
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce15315937
Code: 00 00 e9 a9 fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 5f 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 91 b4 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffe5df53178 EFLAGS: 00000202 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007fce15315937
RDX: 0000000000000000 RSI: 000000006164dc80 RDI: 000055c24a22c02e
RBP: 0000000000000000 R08: 0000000061741e4f R09: 3fffffffffffffff
R10: 4000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 000055c24a247100 R14: 0000000000000001 R15: 0000000000000000