INFO: task syz-executor:5826 blocked for more than 163 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23752 pid:5826 tgid:5826 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1353
deactivate_locked_super+0xc1/0x1b0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xe7/0x110 fs/super.c:503
cleanup_mnt+0x21f/0x450 fs/namespace.c:1318
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
__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_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efd5eb9c117
RSP: 002b:00007ffe16e8d568 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007efd5ec0471f RCX: 00007efd5eb9c117
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe16e8d620
RBP: 00007ffe16e8d620 R08: 00007ffe16e8e620 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe16e8e6b0
R13: 00007efd5ec0471f R14: 000000000009d3e6 R15: 00007ffe16e8e6f0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0:
ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5815:
2 locks held by syz-executor/5826:
#0: ffff8880369800e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880369800e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880369800e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880369800e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz.3.4797/19249:
#0: ffffffff904a2b50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596
2 locks held by syz.1.4851/19392:
4 locks held by syz.1.4991/19776:
3 locks held by kworker/1:1/19848:
#0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90003e0fc98 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888030826240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x63b0 drivers/net/netdevsim/fib.c:1490
2 locks held by syz-executor/19945:
#0: ffff88805ae9c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88805ae9c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88805ae9c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88805ae9c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz-executor/21056:
#0: ffff88805946c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88805946c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88805946c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88805946c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
4 locks held by kworker/u11:0/22436:
#0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90004a47c98 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903f5ce8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
#3: ffffffff8e5ef8f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz-executor/23020:
#0: ffff88805c2aa0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88805c2aa0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88805c2aa0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88805c2aa0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
1 lock held by syz-executor/23775:
#0: ffffffff8e5ef8f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8742 Comm: syz.2.1104 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:page_pool_page_is_pp include/linux/mm.h:4621 [inline]
RIP: 0010:page_expected_state mm/page_alloc.c:1078 [inline]
RIP: 0010:free_page_is_bad mm/page_alloc.c:1117 [inline]
RIP: 0010:free_pages_prepare mm/page_alloc.c:1425 [inline]
RIP: 0010:__free_frozen_pages+0x786/0x1130 mm/page_alloc.c:2973
Code: df 80 3c 02 00 0f 85 0e 08 00 00 4c 89 e2 4d 0b 6f 38 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 e2 07 00 00 <48> ba 40 00 00 00 00 00 ad de 45 31 e4 48 b8 7c 00 00 00 80 ff ff
RSP: 0018:ffffc900038a7960 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8260fa27
RDX: 1ffffd4000319d99 RSI: 0000000000000004 RDI: ffffea00018cecf8
RBP: ffffea00018cecf4 R08: 0000000000000000 R09: fffff94000319d9e
R10: ffffea00018cecf7 R11: 0000000000000000 R12: ffffea00018cecc8
R13: 0000000000000000 R14: 0000000000000000 R15: ffffea00018cecc0
FS: 0000000000000000(0000) GS:ffff8881246e2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb92b9d56b0 CR3: 0000000032a82000 CR4: 00000000003526f0
Call Trace:
vfree.part.0+0x12b/0x9d0 mm/vmalloc.c:3466
vfree+0x55/0x80 mm/vmalloc.c:3443
kcov_put kernel/kcov.c:439 [inline]
kcov_put kernel/kcov.c:435 [inline]
kcov_close+0x34/0x60 kernel/kcov.c:535
__fput+0x3ff/0xb40 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x829/0x2a30 kernel/exit.c:971
do_group_exit+0xd5/0x2a0 kernel/exit.c:1112
get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x86/0x4b0 kernel/entry/common.c:75
__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_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4e7f5b78e
Code: Unable to access opcode bytes at 0x7fc4e7f5b764.
RSP: 002b:00007fc4e61f5f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fc4e61f66c0 RCX: 00007fc4e7f5b78e
RDX: 00007fc4e61f5fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fc4e8008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc4e8216038 R14: 00007fc4e8215fa0 R15: 00007ffc9c4136b8