INFO: task syz-executor:5834 blocked for more than 143 seconds.
Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23768 pid:5834 tgid:5834 ppid:1 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super fs/super.c:506 [inline]
deactivate_super+0xde/0x100 fs/super.c:502
cleanup_mnt+0x225/0x450 fs/namespace.c:1431
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x230 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff0dbf8fc97
RSP: 002b:00007ffc08bca8a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff0dc01089d RCX: 00007ff0dbf8fc97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc08bca960
RBP: 00007ffc08bca960 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc08bcb9f0
R13: 00007ff0dc01089d R14: 000000000004ad6b R15: 00007ffc08bcba30
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3bfa80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3bfa80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e3bfa80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
1 lock held by syslogd/5182:
#0: ffff8880b8439f18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:613 [inline]
#0: ffff8880b8439f18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:598
1 lock held by udevd/5200:
2 locks held by syz-executor/5827:
#0: ffff888051e640e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888051e640e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888051e640e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888051e640e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/5834:
#0: ffff88802b6260e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88802b6260e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88802b6260e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88802b6260e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/5839:
#0: ffff8880650a00e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880650a00e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880650a00e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880650a00e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.0.630/8878:
#0: ffffffff901cc510 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629
2 locks held by syz-executor/9118:
#0: ffff88805f4b20e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88805f4b20e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88805f4b20e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88805f4b20e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.4.694/9223:
#0: ffff8880346780e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880346780e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880346780e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880346780e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/9368:
#0: ffff8880286380e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880286380e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880286380e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880286380e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/10281:
#0: ffff8880343300e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880343300e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880343300e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880343300e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/10537:
#0: ffff88807ebb40e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88807ebb40e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88807ebb40e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88807ebb40e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by getty/10606:
#0: ffff88814da460a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90025a352f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz.7.1002/10635:
#0: ffffffff8e3cafb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x280/0x3c0 kernel/rcu/tree_exp.h:304
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:437
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153
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: 5200 Comm: udevd Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:391 [inline]
RIP: 0010:__rcu_read_lock+0x18/0xf0 kernel/rcu/tree_plugin.h:414
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 65 48 8b 1d f0 2c 03 12 <48> 8d bb 44 04 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83
RSP: 0018:ffffc90003347910 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff88807f6a5a00 RCX: ffffc90003347a80
RDX: 1ffff92000668f44 RSI: ffffffff8dbb90b0 RDI: ffffc900033479e8
RBP: ffffc90003347a30 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000069bf R12: fffff52000668f3f
R13: ffffc900033479e8 R14: ffffc900033479e8 R15: ffffc900033479f0
FS: 00007f8ff0d5f880(0000) GS:ffff8881249e7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561188ab9fb0 CR3: 0000000033716000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_lock include/linux/rcupdate.h:839 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xae/0x20a0 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4744
putname+0x154/0x1a0 fs/namei.c:297
do_unlinkat+0x159/0x6a0 fs/namei.c:4666
__do_sys_unlink fs/namei.c:4689 [inline]
__se_sys_unlink fs/namei.c:4687 [inline]
__x64_sys_unlink+0xc5/0x110 fs/namei.c:4687
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ff0715937
Code: 00 00 e9 a9 fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 5f 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 91 b4 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffcb0a38168 EFLAGS: 00000202 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f8ff0715937
RDX: 0000000000000000 RSI: 000000001be51d00 RDI: 000056093b4ae02e
RBP: 0000000000000000 R08: 000000001be7c2e4 R09: 00007f8ff0e27000
R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000000000
R13: 000056093b4c9100 R14: 0000000000000001 R15: 0000000000000000