INFO: task syz-executor:9111 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21120 pid:9111 tgid:9111 ppid:1 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_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:593
nfsd_umount+0x42/0xd0 fs/nfsd/nfsctl.c:1347
deactivate_locked_super+0xbc/0x130 fs/super.c:473
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f385d1901f7
RSP: 002b:00007ffd7a7d7fb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f385d211d7d RCX: 00007f385d1901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd7a7d8070
RBP: 00007ffd7a7d8070 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd7a7d9100
R13: 00007f385d211d7d R14: 00000000000d9950 R15: 00007ffd7a7d9140
INFO: task syz.9.2110:14639 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2110 state:D stack:28680 pid:14639 tgid:14638 ppid:11001 task_flags:0x400040 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
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:59 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:121
__iterate_supers+0x126/0x290 fs/super.c:922
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75ff58eec9
RSP: 002b:00007f76004ed038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f75ff7e5fa0 RCX: 00007f75ff58eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f75ff7e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75ff7e6038 R14: 00007f75ff7e5fa0 R15: 00007fffd1b9cf98
INFO: task syz.9.2110:14640 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2110 state:D stack:28680 pid:14640 tgid:14638 ppid:11001 task_flags:0x400040 flags:0x00080003
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
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:59 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:121
__iterate_supers+0x126/0x290 fs/super.c:922
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75ff58eec9
RSP: 002b:00007f76004cc038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f75ff7e6090 RCX: 00007f75ff58eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f75ff7e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75ff7e6128 R14: 00007f75ff7e6090 R15: 00007fffd1b9cf98
INFO: task syz.9.2110:14641 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2110 state:D stack:28904 pid:14641 tgid:14638 ppid:11001 task_flags:0x400040 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
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:59 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:121
__iterate_supers+0x126/0x290 fs/super.c:922
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75ff58eec9
RSP: 002b:00007f76004ab038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f75ff7e6180 RCX: 00007f75ff58eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f75ff7e6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75ff7e6218 R14: 00007f75ff7e6180 R15: 00007fffd1b9cf98
INFO: task syz.9.2110:14644 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2110 state:D stack:28904 pid:14644 tgid:14638 ppid:11001 task_flags:0x400040 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
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:59 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:121
__iterate_supers+0x126/0x290 fs/super.c:922
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75ff58eec9
RSP: 002b:00007f760048a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f75ff7e6270 RCX: 00007f75ff58eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f75ff7e6270 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75ff7e6308 R14: 00007f75ff7e6270 R15: 00007fffd1b9cf98
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5626:
#0: ffff88814d42c0a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/9111:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
#1: ffffffff8e621a08 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:593
2 locks held by syz.7.2066/14507:
#0: ffffffff8f7a6390 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e621a08 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1880
1 lock held by syz.9.2110/14639:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.2110/14640:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.2110/14641:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.2110/14644:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.2110/14649:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.2110/14651:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.2110/14654:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.2110/14656:
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880789b40e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
2 locks held by syz.1.2370/15641:
#0: ffffffff8f7a6390 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e621a08 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1880
=============================================
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:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 71 28 00 f3 0f 1e fa fb f4 c8 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 298c86d398c82500 RBX: ffffffff81971c07 RCX: 298c86d398c82500
RDX: 0000000000000001 RSI: ffffffff8dba1162 RDI: ffffffff8c03da60
RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb
R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8fc36c70
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003ad3b58
FS: 0000000000000000(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb6df74860 CR3: 0000000079a60000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147