INFO: task syz.7.5694:25879 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.5694 state:D stack:27368 pid:25879 tgid:25878 ppid:18129 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 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+0x7e6/0x1350 kernel/locking/mutex.c:760
nfsd_nl_listener_get_doit+0x10a/0x5e0 fs/nfsd/nfsctl.c:2069
genl_family_rcv_msg_doit+0x212/0x300 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+0x205/0x470 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+0x82c/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:742
____sys_sendmsg+0x505/0x830 net/socket.c:2630
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
__sys_sendmsg net/socket.c:2716 [inline]
__do_sys_sendmsg net/socket.c:2721 [inline]
__se_sys_sendmsg net/socket.c:2719 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff7b8d8eec9
RSP: 002b:00007ff7b9b97038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff7b8fe5fa0 RCX: 00007ff7b8d8eec9
RDX: 0000000024000100 RSI: 0000200000001740 RDI: 0000000000000007
RBP: 00007ff7b8e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff7b8fe6038 R14: 00007ff7b8fe5fa0 R15: 00007ffc05d37478
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8dd3a860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8dd3a860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8dd3a860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5602:
#0: ffff88814d8370a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036be2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:6/5967:
#0: ffff88801a081148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801a081148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004547bc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004547bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8dd402f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8dd402f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
1 lock held by udevd/5998:
#0: ffff888142fc4358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
2 locks held by syz.9.5567/25436:
#0: ffffffff8f12a5d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e01edc8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919
2 locks held by syz.7.5694/25879:
#0: ffffffff8f12a5d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e01edc8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0 fs/nfsd/nfsctl.c:2069
1 lock held by syz-executor/26114:
1 lock held by syz.1.6128/27501:
#0: ffff888069e8e6e0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2269
3 locks held by syz.1.6128/27508:
#0: ffffffff8f12a5d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffff888069e8e6e0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2406
#2: ffffffff8e01edc8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdf/0x1290 fs/nfsd/nfsctl.c:1516
2 locks held by syz.4.6377/28403:
#0: ffffffff8f12a5d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e01edc8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919
2 locks held by syz.8.6480/28756:
#0: ffffffff8f12a5d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e01edc8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919
2 locks held by syz.0.6568/29024:
#0: ffffffff8f12a5d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e01edc8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20658 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline]
RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2170 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock+0x12e/0x290 kernel/locking/spinlock_debug.c:116
Code: 00 48 89 df be 04 00 00 00 e8 ee 6e 86 00 48 8d 7c 24 40 be 04 00 00 00 e8 df 6e 86 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 dd 00 00 00 65 8b 1d d9 9b ab 10 48 b9 00 00 00 00 00 fc ff
RSP: 0018:ffffc9001817f720 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff99770fc0 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9001817f760
RBP: ffffc9001817f7d0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200302feec R12: ffffffff99770fd0
R13: ffffffff99770fc8 R14: 1ffffffff32ee1fa R15: 1ffffffff32ee1f9
FS: 0000000000000000(0000) GS:ffff88812649b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056027c13e000 CR3: 000000007d4b8000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
_raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162
__debug_check_no_obj_freed lib/debugobjects.c:1088 [inline]
debug_check_no_obj_freed+0x17a/0x470 lib/debugobjects.c:1129
slab_free_hook mm/slub.c:2353 [inline]
slab_free mm/slub.c:4695 [inline]
kmem_cache_free+0x113/0x400 mm/slub.c:4797
nsim_dev_trap_report drivers/net/netdevsim/dev.c:836 [inline]
nsim_dev_trap_report_work+0x7cf/0xb80 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245