INFO: task syz.2.1697:11292 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1697 state:D stack:26440 pid:11292 tgid:11291 ppid:5820 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:6946 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6961
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018
__mutex_lock_common kernel/locking/mutex.c:686 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:770
nfsd_nl_listener_set_doit+0x137/0x1660 fs/nfsd/nfsctl.c:1880
genl_family_rcv_msg_doit+0x215/0x300 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:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:728
__sock_sendmsg net/socket.c:743 [inline]
____sys_sendmsg+0x577/0x880 net/socket.c:2601
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2655
__sys_sendmsg net/socket.c:2687 [inline]
__do_sys_sendmsg net/socket.c:2692 [inline]
__se_sys_sendmsg net/socket.c:2690 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2690
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efc0dd8f749
RSP: 002b:00007efc0ebd8038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efc0dfe5fa0 RCX: 00007efc0dd8f749
RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007efc0de13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efc0dfe6038 R14: 00007efc0dfe5fa0 R15: 00007ffd3b007b48
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33d820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33d820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33d820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5578:
#0: ffff8880302c40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
5 locks held by kworker/u8:11/5930:
2 locks held by syz.3.1656/11192:
#0: ffffffff8f75c8f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e62cd48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1660 fs/nfsd/nfsctl.c:1880
2 locks held by syz.2.1697/11292:
#0: ffffffff8f75c8f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e62cd48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1660 fs/nfsd/nfsctl.c:1880
2 locks held by syz.1.1937/12112:
#0: ffffffff8f75c8f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e62cd48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1660 fs/nfsd/nfsctl.c:1880
2 locks held by syz.5.1954/12154:
#0: ffffffff8f75c8f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e62cd48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1660 fs/nfsd/nfsctl.c:1880
=============================================
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 10/25/2025
Call Trace:
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]
__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:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12247 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:syscall_return_via_sysret+0x1a/0x87
Code: 1c 00 00 e8 50 df 61 0a 84 c0 0f 84 38 15 00 00 66 90 b9 48 00 00 00 65 48 8b 15 d1 83 be 11 83 e2 fe 89 d0 48 c1 ea 20 0f 30 <41> 5f 41 5e 41 5d 41 5c 5d 5b 41 5b 41 5a 41 59 41 58 58 59 5a 5e
RSP: 0018:ffffc9000423ff48 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000048
RDX: 0000000000000000 RSI: ffffffff8da6f7a8 RDI: ffffffff8be147e0
RBP: 0000000000000000 R08: ffffffff8fbf8d77 R09: 1ffffffff1f7f1ae
R10: dffffc0000000000 R11: fffffbfff1f7f1af R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 000055557ed25500(0000) GS:ffff888125a3b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49cf972a60 CR3: 000000002fd14000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
RIP: 0033:0x7f9256bc2005
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:00007ffd9aade1d0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000000000000117 RCX: 00007f9256bc2005
RDX: 00007ffd9aade210 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd9aade27c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 0000000000085f59 R15: 00007ffd9aade2d0