INFO: task syz.1.3835:18839 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3835 state:D stack:27144 pid:18839 tgid:18838 ppid:15457 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1743
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:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8421f9c799
RSP: 002b:00007f8422dc0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8422215fa0 RCX: 00007f8421f9c799
RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007f8422032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8422216038 R14: 00007f8422215fa0 R15: 00007ffc0a6f6468
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5578:
#0: ffff8880371880a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by syz.3.1769/11899:
#0: ffffffff8fc3ad30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ea858a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b5/0x9a0 fs/nfsd/nfsctl.c:1597
1 lock held by syz-executor/15132:
#0: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
#0: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: unwind_next_frame+0xa5/0x23c0 arch/x86/kernel/unwind_orc.c:495
1 lock held by udevd/15136:
#0: ffff888026cfa358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by syz-executor/16409:
2 locks held by syz.1.3835/18839:
#0: ffffffff8fc3ad30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ea858a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1743
3 locks held by kworker/1:7/20276:
3 locks held by kworker/1:8/20280:
#0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc9000c1cfc40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000c1cfc40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
10 locks held by syz.6.5181/23755:
=============================================
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 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:161 [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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 16409 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline]
RIP: 0010:lock_acquire+0x79/0x2e0 kernel/locking/lockdep.c:5844
Code: 0e 73 0d e8 d9 29 09 00 84 c0 0f 84 bc 01 00 00 83 3d ea 41 70 0e 00 0f 84 c3 00 00 00 48 8b 74 24 68 4c 89 ef e8 c7 25 8e 00 <83> 3d d0 41 70 0e 00 0f 84 c1 00 00 00 65 8b 05 b3 bd 7a 11 85 c0
RSP: 0018:ffffc900038074e0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff81ae94b6 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff81767e02 RDI: 1ffffffff1cebc84
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003807678 R11: ffffffff81b0bfa0 R12: 0000000000000002
R13: ffffffff8e75e420 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc2607d3e9c CR3: 000000000e54c000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
vfree+0x25a/0x400 mm/vmalloc.c:3479
kcov_put kernel/kcov.c:442 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:543
__fput+0x44f/0xa70 fs/file_table.c:469
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x23c0 kernel/exit.c:976
do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
get_signal+0x1284/0x1330 kernel/signal.c:3034
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbe6715cfce
Code: Unable to access opcode bytes at 0x7fbe6715cfa4.
RSP: 002b:00007ffdf1b9b948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00005555750f9500 RCX: 00007fbe6715cfce
RDX: 00007ffdf1b9b9a0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffdf1b9ba0c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388
R13: 00000000000927c0 R14: 0000000000094710 R15: 00007ffdf1b9ba60