INFO: task syz-executor:5997 blocked for more than 143 seconds.
Not tainted 6.16.0-syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:20000 pid:5997 tgid:5997 ppid:1 task_flags:0x40014c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:596
nfsd_umount+0x42/0xd0 fs/nfsd/nfsctl.c:1386
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417
task_work_run+0x1d1/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x22e0 kernel/exit.c:964
do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
__do_sys_exit_group kernel/exit.c:1116 [inline]
__se_sys_exit_group kernel/exit.c:1114 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7f8aa2b8ebe9
RSP: 002b:00007fffd70be818 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f8aa2c11c77 RCX: 00007f8aa2b8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000016 R08: 00007fffd70bc5b6 R09: 00007fffd70bfad0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffd70bfad0
R13: 00007f8aa2c11c05 R14: 00005555675174a8 R15: 00007fffd70c4f60
Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
#0: ffff888146aec148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff888146aec148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
2 locks held by rcu_tasks_trace/29:
#0: ffffffff8e13fe10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0 kernel/rcu/tasks.h:614
#1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
1 lock held by khungtaskd/31:
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5599:
#0: ffff888030d030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/5997:
#0: ffff8880635fc0e0 (&type->s_umount_key#96){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880635fc0e0 (&type->s_umount_key#96){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880635fc0e0 (&type->s_umount_key#96){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffffffff8e41a568 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:596
2 locks held by syz.1.2653/16131:
#0: ffffffff8f5701f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e41a568 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1922
1 lock held by syz.3.3111/17802:
#0: ffff8880635fc0e0 (&type->s_umount_key#96){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880635fc0e0 (&type->s_umount_key#96){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
2 locks held by kworker/u8:22/17947:
#0: ffff888146aec148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff888146aec148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90003b47bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003b47bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
1 lock held by syz.0.3401/18844:
#0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998
3 locks held by syz.4.3404/18867:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 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: 18867 Comm: syz.4.3404 Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:gup_must_unshare+0x0/0x6f0 mm/internal.h:1446
Code: 41 5e 41 5f 5d c3 cc cc cc cc cc 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 48 89 d3 89 f5 49 89 ff e8 c9 cb ba
RSP: 0018:ffffc9000d0bee78 EFLAGS: 00000293
RAX: ffffffff82057777 RBX: ffffea00013b6408 RCX: ffff88806b469e00
RDX: ffffea0001d06bc0 RSI: 000000000000000e RDI: ffff88805b94c640
RBP: ffffc9000d0bef70 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001a17db0 R12: 000000000000000e
R13: ffffea0001d06bc8 R14: dffffc0000000000 R15: ffffea0001d06bc0
FS: 00007f4042db46c0(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b14184198 CR3: 000000006acf4000 CR4: 00000000003526f0
Call Trace:
follow_page_pte+0x79e/0x14b0 mm/gup.c:897
follow_pmd_mask mm/gup.c:971 [inline]
follow_pud_mask mm/gup.c:1023 [inline]
follow_p4d_mask mm/gup.c:1040 [inline]
follow_page_mask mm/gup.c:1083 [inline]
__get_user_pages+0xbad/0x30b0 mm/gup.c:1486
__get_user_pages_locked mm/gup.c:1754 [inline]
get_dump_page+0x1ac/0x3f0 mm/gup.c:2258
dump_user_range+0x1de/0xc70 fs/coredump.c:1180
elf_core_dump+0x32ed/0x3900 fs/binfmt_elf.c:2075
do_coredump+0x2809/0x3440 fs/coredump.c:950
get_signal+0x10d9/0x1310 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:184
exc_page_fault+0x9f/0xf0 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f4041f8ebf1
Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:0000000000000030 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f40421b5fa0 RCX: 00007f4041f8ebe9
RDX: 0000000000000000 RSI: 0000000000000030 RDI: 0000000000000600
RBP: 00007f4042011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f40421b6038 R14: 00007f40421b5fa0 R15: 00007fff825bf388