INFO: task syz.4.2988:13947 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2988      state:D stack:25192 pid:13947 tgid:13946 ppid:5863   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 nfsd_nl_threads_set_doit+0x2cb/0x960 fs/nfsd/nfsctl.c:1629
 genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f757df8ebe9
RSP: 002b:00007f757eeb7038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f757e1b5fa0 RCX: 00007f757df8ebe9
RDX: 0000000000008004 RSI: 0000200000000180 RDI: 0000000000000008
RBP: 00007f757e011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f757e1b6038 R14: 00007f757e1b5fa0 R15: 00007fff7afb3f38
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14406 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217
Code: 08 60 a0 92 65 8b 15 e8 b4 e0 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 <83> fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c
RSP: 0018:ffffc90003987028 EFLAGS: 00000046
RAX: ffffffff81c389fb RBX: ffff88801d6d25b0 RCX: ffff888050e8bc00
RDX: 0000000000000000 RSI: ffffffff8e18ed80 RDI: 0000000000000004
RBP: 00000061354cf69d R08: ffff888050e8bc00 R09: 0000000000000020
R10: 000000000000001f R11: 0000000000000000 R12: ffff88801d6d2010
R13: ffff88801d6d2010 R14: 00000061354d4b62 R15: 00000000000005b4
FS:  0000555587f5c500(0000) GS:ffff888125d1a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdbb4a7be8 CR3: 000000007e9c6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rb_read_data_buffer+0x44b/0x580 kernel/trace/ring_buffer.c:1823
 check_buffer+0x28a/0x750 kernel/trace/ring_buffer.c:4394
 __rb_reserve_next+0x592/0xdb0 kernel/trace/ring_buffer.c:4493
 rb_reserve_next_event kernel/trace/ring_buffer.c:4630 [inline]
 ring_buffer_lock_reserve+0xbb5/0x1010 kernel/trace/ring_buffer.c:4689
 __trace_buffer_lock_reserve kernel/trace/trace.c:1077 [inline]
 trace_event_buffer_lock_reserve+0x1d0/0x6f0 kernel/trace/trace.c:2789
 trace_event_buffer_reserve+0x248/0x340 kernel/trace/trace_events.c:672
 do_trace_event_raw_event_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline]
 trace_event_raw_event_bpf_trace_printk+0x100/0x260 kernel/trace/bpf_trace.h:11
 __do_trace_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline]
 trace_bpf_trace_printk+0x170/0x1d0 kernel/trace/bpf_trace.h:11
 ____bpf_trace_printk kernel/trace/bpf_trace.c:380 [inline]
 bpf_trace_printk+0x11e/0x190 kernel/trace/bpf_trace.c:363
 bpf_prog_9e1c00255e17e72e+0x39/0x3f
 bpf_dispatcher_nop_func include/linux/bpf.h:1335 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline]
 bpf_trace_run1+0x27f/0x4b0 kernel/trace/bpf_trace.c:2297
 __bpf_trace_rcu_utilization+0xa1/0xf0 include/trace/events/rcu.h:27
 __do_trace_rcu_utilization include/trace/events/rcu.h:27 [inline]
 trace_rcu_utilization+0x1ad/0x1d0 include/trace/events/rcu.h:27
 rcu_note_context_switch+0xdc1/0x1140 kernel/rcu/tree_plugin.h:372
 __schedule+0x35d/0x4cc0 kernel/sched/core.c:6846
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 do_nanosleep+0x1c7/0x600 kernel/time/hrtimer.c:2100
 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2147
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline]
 __se_sys_clock_nanosleep+0x2ee/0x380 kernel/time/posix-timers.c:1376
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75b13c14a5
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007ffc53cdc800 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000273 RCX: 00007f75b13c14a5
RDX: 00007ffc53cdc840 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc53cdc8ac R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 0000000000065b4d R15: 00007ffc53cdc900
 </TASK>