INFO: task syz-executor:6856 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23416 pid:6856 tgid:6856 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: 0033:0x7f370799c117
RSP: 002b:00007ffde0b3dd38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3707a0471f RCX: 00007f370799c117
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffde0b3ddf0
RBP: 00007ffde0b3ddf0 R08: 00007ffde0b3edf0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde0b3ee80
R13: 00007f3707a0471f R14: 00000000000a590d R15: 00007ffde0b3eec0
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]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:2/3568:
1 lock held by dhcpcd/5491:
#0: ffffffff903f5828 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff903f5828 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x1b4/0x320 net/ipv6/addrconf.c:4799
4 locks held by kworker/u10:6/6754:
#0: ffff88801c29f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9001859fc98 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903dcef0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x830 net/core/net_namespace.c:670
#3: ffffffff903f5828 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x17/0x120 net/wireless/core.c:1693
2 locks held by syz-executor/6856:
#0: ffff888052ad80e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888052ad80e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888052ad80e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888052ad80e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
1 lock held by syz.1.1160/11170:
3 locks held by kworker/u10:10/11258:
#0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90003a2fc98 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903f5828 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303
2 locks held by syz.5.1543/13170:
#0: ffffffff904a2690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596
2 locks held by syz.2.1831/14373:
#0: ffffffff904a2690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1886
3 locks held by kworker/u10:4/15583:
#0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9000bfafc98 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888029dc8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6360 [inline]
#2: ffff888029dc8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x92/0x560 net/wireless/core.c:424
1 lock held by syz.6.2227/15959:
#0: ffff88803b88a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803b88a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: super_lock+0x1ca/0x3f0 fs/super.c:121
2 locks held by syz.6.2227/15963:
#0: ffff88803b88a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803b88a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88803b88a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88803b88a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
1 lock held by syz.9.2312/16488:
#0: ffff88805d041ec8 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff88805d041ec8 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:661
4 locks held by syz.9.2315/16536:
#0: ffffffff904a2690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff903f5828 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0xb4/0xae0 net/wireless/nl80211.c:17922
#2: ffff888029dc8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6360 [inline]
#2: ffff888029dc8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_netdev_notifier_call+0x54f/0x10e0 net/wireless/core.c:1591
#3: ffffffff8e5ef8f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
3 locks held by syz.7.2316/16531:
#0: ffff88803516a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline]
#0: ffff88803516a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:345 [inline]
#0: ffff88803516a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
#0: ffff88803516a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x80/0x2f0 drivers/tty/tty_ldisc.c:780
#1: ffff88803516f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:295 [inline]
#1: ffff88803516f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:347 [inline]
#1: ffff88803516f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
#1: ffff88803516f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xae/0x2f0 drivers/tty/tty_ldisc.c:780
#2: ffffffff903f5828 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff903f5828 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2156
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16517 Comm: syz.0.2279 Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:kasan_check_range+0xfc/0x1e0 mm/kasan/generic.c:201
Code: c0 01 48 39 c2 74 1d 80 38 00 74 f2 ba 01 00 00 00 48 85 c0 74 2c 41 83 e2 07 49 39 c1 75 15 45 3a 11 7d 10 ba 01 00 00 00 5b <5d> 89 d0 41 5c c3 cc cc cc cc 41 0f b6 d0 e8 d1 e4 ff ff 83 f0 01
RSP: 0018:ffffc9001c4e7990 EFLAGS: 00000246
RAX: fffff940004a21ef RBX: 0000000000000000 RCX: ffffffff82610179
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea0002510f74
RBP: fffff940004a21ee R08: 0000000000000000 R09: fffff940004a21ee
R10: ffffea0002510f77 R11: 0000000000000000 R12: ffffea0002510f40
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88805ad6d480
FS: 0000000000000000(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d2bdff8 CR3: 0000000034860000 CR4: 00000000003526f0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
page_ref_count include/linux/page_ref.h:67 [inline]
put_page_testzero include/linux/mm.h:1292 [inline]
___free_pages+0x89/0x220 mm/page_alloc.c:5320
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: 0033:0x7efda7b9aeb9
Code: Unable to access opcode bytes at 0x7efda7b9ae8f.
RSP: 002b:00007efda8a55028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: fffffffffffffffc RBX: 00007efda7e16090 RCX: 00007efda7b9aeb9
RDX: 0000000000000017 RSI: ffffffffffff0005 RDI: 0000000000000000
RBP: 00007efda7c08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efda7e16128 R14: 00007efda7e16090 R15: 00007ffe26107e08