INFO: task syz.7.3682:20780 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.3682 state:D stack:27104 pid:20780 tgid:20779 ppid:20392 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5354 [inline]
__schedule+0x165c/0x5520 kernel/sched/core.c:6966
__schedule_loop kernel/sched/core.c:7049 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7064
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7121
__mutex_lock_common kernel/locking/mutex.c:710 [inline]
__mutex_lock+0x856/0x1420 kernel/locking/mutex.c:794
nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633
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:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:786 [inline]
__sock_sendmsg net/socket.c:801 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2650
___sys_sendmsg+0x2a5/0x360 net/socket.c:2704
__sys_sendmsg net/socket.c:2736 [inline]
__do_sys_sendmsg net/socket.c:2741 [inline]
__se_sys_sendmsg net/socket.c:2739 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f546f59c799
RSP: 002b:00007f54703e8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f546f815fa0 RCX: 00007f546f59c799
RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007f546f632c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f546f816038 R14: 00007f546f815fa0 R15: 00007ffd4436c218
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e75d0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75d0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75d0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5596:
#0: ffff888032e540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000321e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
9 locks held by kworker/1:6/5921:
2 locks held by syz.2.3684/20766:
#0: ffffffff8fc46548 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ea87760 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633
2 locks held by syz.7.3682/20780:
#0: ffffffff8fc46548 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ea87760 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633
5 locks held by kworker/u8:4/22165:
#0: ffff88801bae6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3253 [inline]
#0: ffff88801bae6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3361
#1: ffffc90005187c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3254 [inline]
#1: ffffc90005187c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3361
#2: ffffffff8fbc9708 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
#3: ffffffff8fbd8000 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff8fbd8000 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248
#4: ffffffff8e7633e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#4: ffffffff8e7633e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by dhcpcd-run-hook/23231:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+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: 23235 Comm: dhcpcd-run-hook Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_preemption_disabled+0x22/0xe0 lib/smp_processor_id.c:53
Code: 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 b7 90 6b 07 65 8b 0d ac 90 6b 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d 89 d0 02 00 cc 9c 59 f7 c1 00 02 00 00 74 ea 65 4c 8b 3d 5e 90
RSP: 0018:ffffc90004a87748 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000046
RDX: 00000000e8936300 RSI: ffffffff8df61b58 RDI: ffffffff8c288380
RBP: ffffc90004a878d0 R08: ffffffff81b3b919 R09: ffffffff9a2db488
R10: dffffc0000000000 R11: fffffbfff202515f R12: dffffc0000000000
R13: ffffffff81b3b919 R14: ffffffff9a2db488 R15: ffff888028d03d00
FS: 00007fa00a956c80(0000) GS:ffff88812543f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa00aa47080 CR3: 0000000075b3e000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
lock_release+0xa1/0x3c0 kernel/locking/lockdep.c:5888
seqcount_lockdep_reader_access+0xa4/0x100 include/linux/seqlock.h:74
ktime_get_coarse_real_ts64_mg+0x59/0x1e0 kernel/time/timekeeping.c:2605
current_time+0x96/0x370 fs/inode.c:2376
atime_needs_update+0x320/0x6d0 fs/inode.c:2236
pick_link+0x543/0xfe0 fs/namei.c:2040
step_into_slowpath+0x547/0x7e0 fs/namei.c:2123
step_into fs/namei.c:2148 [inline]
walk_component fs/namei.c:2284 [inline]
link_path_walk+0xd50/0x18d0 fs/namei.c:2652
path_lookupat+0xe4/0x8c0 fs/namei.c:2808
filename_lookup+0x256/0x5d0 fs/namei.c:2838
__do_sys_chdir fs/open.c:559 [inline]
__se_sys_chdir+0xa8/0x2a0 fs/open.c:552
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa00ab102f7
Code: 77 01 c3 48 8b 15 01 fb 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 50 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d d1 fa 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffdea387b58 EFLAGS: 00000206 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa00ab102f7
RDX: 00007ffdea387b80 RSI: 00007fa00aca3eb3 RDI: 0000564bc12eb000
RBP: 0000564bc12eaf58 R08: 0000564bc12eaff0 R09: 0000000000000020
R10: 0000000000000000 R11: 0000000000000206 R12: 0000564bc12eb000
R13: 0000564bc12dac30 R14: 0000564bc12eb000 R15: 0000564bc12eb026