INFO: task syz.2.1549:13323 blocked for more than 143 seconds.
Tainted: G U syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1549 state:D stack:28376 pid:13323 tgid:13317 ppid:5839 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x158/0x420 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+0x5a7/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2617
___sys_sendmsg+0x134/0x1d0 net/socket.c:2671
__sys_sendmsg+0x16d/0x220 net/socket.c:2703
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff416b8eec9
RSP: 002b:00007ff417a9c038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff416de6090 RCX: 00007ff416b8eec9
RDX: 0000000000000080 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007ff416c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff416de6128 R14: 00007ff416de6090 R15: 00007ffc97d4dd48
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e1c34a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e1c34a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e1c34a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5834:
#0: ffff88802a7560e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802a7560e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802a7560e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88802a7560e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e5e4e28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by getty/11893:
#0: ffff88814d34a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90002f502f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/13122:
#0: ffff888075f500e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888075f500e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888075f500e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888075f500e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e5e4e28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.2.1549/13318:
#0: ffffffff8ff81f90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e4e28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.2.1549/13323:
#0: ffffffff8ff81f90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e4e28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.4.1957/15377:
#0: ffffffff8fede948 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fede948 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436
#1: ffffffff8e1cea38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/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+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
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: 5190 Comm: syslogd Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline]
RIP: 0010:__pvclock_clocksource_read arch/x86/kernel/pvclock.c:77 [inline]
RIP: 0010:pvclock_clocksource_read_nowd+0x1a/0x100 arch/x86/kernel/pvclock.c:120
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 54 55 53 48 89 fb 48 83 ec 10 8b 17 83 e2 fe 41 89 d4 0f 01 f9 <66> 90 48 c1 e2 20 8b 6b 18 48 09 c2 48 89 d0 0f be 53 1c 48 2b 43
RSP: 0018:ffffc90002ee7700 EFLAGS: 00000002
RAX: 0000000095436454 RBX: ffffffff93826000 RCX: 0000000000000000
RDX: 0000000000000167 RSI: ffffffff815f4b2b RDI: ffffffff93826000
RBP: 0000000000000004 R08: dc1b76dbd546da80 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000000 R12: 000000000000000e
R13: ffff8880b8624080 R14: 0000000000000000 R15: ffff88807b3b0000
FS: 00007fa6605e4c80(0000) GS:ffff888124e5d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33fe5ff8 CR3: 000000007c35c000 CR4: 00000000003526f0
Call Trace:
kvm_sched_clock_read+0x11/0x20 arch/x86/kernel/kvmclock.c:91
sched_clock+0x17/0x60 arch/x86/kernel/tsc.c:288
sched_clock_cpu+0x6c/0x530 kernel/sched/clock.c:397
cpu_clock include/linux/sched/clock.h:93 [inline]
psi_task_change+0x18a/0x540 kernel/sched/psi.c:920
psi_enqueue kernel/sched/stats.h:166 [inline]
enqueue_task+0x20e/0x4e0 kernel/sched/core.c:2094
activate_task kernel/sched/core.c:2134 [inline]
ttwu_do_activate+0x17e/0xb00 kernel/sched/core.c:3706
ttwu_queue kernel/sched/core.c:3969 [inline]
try_to_wake_up+0x7a1/0x1870 kernel/sched/core.c:4293
autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:403
__wake_up_common+0x135/0x1f0 kernel/sched/wait.c:108
__wake_up_common_lock kernel/sched/wait.c:125 [inline]
__wake_up_sync_key+0x36/0x50 kernel/sched/wait.c:192
__unix_dgram_recvmsg+0x315/0xc30 net/unix/af_unix.c:2626
unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2700
sock_recvmsg_nosec net/socket.c:1065 [inline]
sock_recvmsg+0x1f6/0x250 net/socket.c:1087
sock_read_iter+0x2b9/0x3b0 net/socket.c:1157
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0xa95/0xcf0 fs/read_write.c:572
ksys_read+0x1f8/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa660734407
Code: 48 89 fa 4c 89 df e8 38 aa 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:00007ffe31e675d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fa6605e4c80 RCX: 00007fa660734407
RDX: 00000000000000ff RSI: 0000564cad218950 RDI: 0000000000000000
RBP: 0000564cad218910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000564cad218982
R13: 0000000000000000 R14: 0000564cad218950 R15: 0000564c84673d98