INFO: task syz.2.1445:10997 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1445 state:D stack:27000 pid:10997 tgid:10996 ppid:5622 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
nfsd_nl_svc_export_set_reqs_doit+0x132/0x1450 fs/nfsd/export.c:1057
genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
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: 0033:0x7fe7be79de99
RSP: 002b:00007fe7bf6f9028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe7bea25fa0 RCX: 00007fe7be79de99
RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000009
RBP: 00007fe7be833eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7bea26038 R14: 00007fe7bea25fa0 R15: 00007ffdbcd714e8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:7/1121:
2 locks held by getty/5380:
#0: ffff8880324390a0 (&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+0x45a/0x1360 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:12/8844:
2 locks held by syz.3.1311/10514:
#0: ffffffff9009daa8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e5a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964
2 locks held by syz.2.1445/10997:
#0: ffffffff9009daa8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e5a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_set_reqs_doit+0x132/0x1450 fs/nfsd/export.c:1057
2 locks held by syz.1.2540/15068:
#0: ffffffff9009daa8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e5a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_unlock_filesystem_doit+0x2af/0x400 fs/nfsd/nfsctl.c:2345
2 locks held by syz.4.2779/16047:
#0: ffffffff9009daa8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e5a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_unlock_filesystem_doit+0x2af/0x400 fs/nfsd/nfsctl.c:2345
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
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+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5610 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:hrtimer_base_is_online kernel/time/hrtimer.c:127 [inline]
RIP: 0010:__hrtimer_start_range_ns kernel/time/hrtimer.c:1431 [inline]
RIP: 0010:hrtimer_start_range_ns_common+0x7fb/0xb90 kernel/time/hrtimer.c:1481
Code: df e8 19 34 81 00 48 8b 1b 4c 89 f7 48 89 de e8 6b a3 13 00 49 39 de 7e 4c e8 01 a1 13 00 eb 2c 48 8b 44 24 40 42 0f b6 04 28 <84> c0 0f 85 ee 02 00 00 41 80 3f 01 0f 85 44 01 00 00 e8 de a0 13
RSP: 0018:ffffc9000384fb48 EFLAGS: 00000083
RAX: 0000000000000000 RBX: ffffc9000384fd40 RCX: ffff8880368c3e00
RDX: 0000000000000000 RSI: ffff8880b86282d8 RDI: ffffc9000384fd40
RBP: 1ffff92000709f01 R08: ffffc9000384fd57 R09: 0000000000000000
R10: ffffc9000384fd48 R11: fffff52000709fab R12: ffff8880b86281c0
R13: dffffc0000000000 R14: ffff8880b862820d R15: ffff8880b8628211
FS: 0000555567788540(0000) GS:ffff888124f50000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564df45b1660 CR3: 000000007cfec000 CR4: 00000000003526f0
Call Trace:
hrtimer_start_range_ns_user+0x113/0x430 kernel/time/hrtimer.c:1577
hrtimer_start_expires_user include/linux/hrtimer.h:248 [inline]
hrtimer_sleeper_start_expires kernel/time/hrtimer.c:2319 [inline]
do_nanosleep+0x16c/0x6a0 kernel/time/hrtimer.c:2396
hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2445
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1406 [inline]
__se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1383
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: 0033:0x7ff76f759017
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe6c9eca80 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000555567788540 RCX: 00007ff76f759017
RDX: 00007ffe6c9ecac0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe6c9ecfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffe6c9ecafc R14: 00007ffe6c9ecb90 R15: 0000000000000000