INFO: task syz.5.3607:19725 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.3607 state:D stack:25352 pid:19725 tgid:19723 ppid:17909 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_get_doit+0x17c/0xc40 fs/nfsd/nfsctl.c:1873
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: 0033:0x7fbb89f9ce59
RSP: 002b:00007fbb8aebb028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbb8a215fa0 RCX: 00007fbb89f9ce59
RDX: 0000000020000000 RSI: 0000200000000140 RDI: 000000000000000a
RBP: 00007fbb8a032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbb8a216038 R14: 00007fbb8a215fa0 R15: 00007fffb88fe268
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5386:
#0: ffff888036d2f0a0 (&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
2 locks held by syz.1.3111/17484:
#0: ffffffff8fe386a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8b280 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
2 locks held by syz.5.3607/19725:
#0: ffffffff8fe386a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8b280 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xc40 fs/nfsd/nfsctl.c:1873
5 locks held by kworker/u8:33/21733:
#0: ffff8880b863b0e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff8880b8626118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1117
#3: ffffffff9a673228 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x83/0x580 lib/debugobjects.c:845
#4: ffff8880521f0ed8 (&bat_priv->forw_bat_list_lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
#4: ffff8880521f0ed8 (&bat_priv->forw_bat_list_lock){+...}-{3:3}, at: batadv_forw_packet_queue+0x33/0x240 net/batman-adv/send.c:660
1 lock held by udevd/24279:
#0: ffff88802787b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953
2 locks held by syz.6.4859/24401:
#0: ffffffff8fe386a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8b280 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
2 locks held by syz.2.4875/24452:
#0: ffffffff8fdc8c80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdc8c80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3441
#1: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
2 locks held by dhcpcd-run-hook/24479:
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 24485 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:preempt_latency_start kernel/sched/core.c:5839 [inline]
RIP: 0010:preempt_count_add+0xa6/0x190 kernel/sched/core.c:5862
Code: ff ff ff 7f 39 f8 75 42 48 8b 5c 24 18 48 89 df e8 7f 68 0e 00 85 c0 74 09 31 db 31 ff e8 72 68 0e 00 65 4c 8b 35 d2 37 a4 11 <49> 81 c6 70 15 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c
RSP: 0018:ffffc9000feaf5c8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff82430683 RCX: ffffffff9a436300
RDX: 0000000000000000 RSI: ffffffff8e217368 RDI: ffffffff82430683
RBP: ffffc9000feaf780 R08: ffff888050a86443 R09: 1ffff1100a150c88
R10: dffffc0000000000 R11: ffffed100a150c89 R12: dffffc0000000000
R13: 1ffff1100a150c81 R14: ffff88807da40000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881252a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fef4e117286 CR3: 0000000057d44000 CR4: 00000000003526f0
Call Trace:
class_preempt_constructor include/linux/preempt.h:468 [inline]
file_ref_put include/linux/file_ref.h:150 [inline]
fput+0x23/0xd0 fs/file_table.c:586
remove_vma+0xdf/0x130 mm/vma.c:471
tear_down_vmas+0x312/0x520 mm/mmap.c:1262
exit_mmap+0x4b6/0x9e0 mm/mmap.c:1320
__mmput+0x118/0x430 kernel/fork.c:1178
exec_mmap+0x3b4/0x440 fs/exec.c:893
begin_new_exec+0x134a/0x2480 fs/exec.c:1148
load_elf_binary+0xa47/0x2980 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1664 [inline]
exec_binprm fs/exec.c:1696 [inline]
bprm_execve+0x94a/0x1510 fs/exec.c:1748
do_execveat_common+0x50d/0x690 fs/exec.c:1846
__do_sys_execve fs/exec.c:1930 [inline]
__se_sys_execve fs/exec.c:1924 [inline]
__x64_sys_execve+0x97/0xc0 fs/exec.c:1924
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: 0033:0x7fef4e05d107
Code: Unable to access opcode bytes at 0x7fef4e05d0dd.
RSP: 002b:00007ffe25b91638 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00005595473851d8 RCX: 00007fef4e05d107
RDX: 0000559547380e58 RSI: 00005595473851d8 RDI: 0000559547380ee8
RBP: 0000559547380ee8 R08: 00007ffe25b94e82 R09: 0000000000000210
R10: 0000000000000002 R11: 0000000000000246 R12: 0000559547380e58
R13: 00007fef4e222e8b R14: 0000559547380e58 R15: 0000000000000000