INFO: task syz.1.1768:11024 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1768 state:D stack:28080 pid:11024 tgid:11023 ppid:10488 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
__super_lock fs/super.c:57 [inline]
super_lock+0x25c/0x3b0 fs/super.c:121
user_get_super+0xc8/0x120 fs/super.c:998
quotactl_block fs/quota/quota.c:890 [inline]
__do_sys_quotactl fs/quota/quota.c:955 [inline]
__se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1aa898f749
RSP: 002b:00007f1aa988e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f1aa8be5fa0 RCX: 00007f1aa898f749
RDX: 0000000000000000 RSI: 0000200000000180 RDI: ffffffff80000201
RBP: 00007f1aa8a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1aa8be6038 R14: 00007f1aa8be5fa0 R15: 00007ffc07dcd7d8
Showing all locks held in the system:
5 locks held by kworker/1:0/24:
#0: ffff88801fa83d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88801fa83d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc900001e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc900001e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888143ba0198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888143ba0198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff88804d153198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88804d153198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
#4: ffff88804d151160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88804d151160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
1 lock held by khungtaskd/32:
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5581:
#0: ffff88814d6330a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5823:
1 lock held by syz-executor/8963:
1 lock held by syz.1.1768/11024:
#0: ffff8880482d40e0 (&type->s_umount_key#107){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880482d40e0 (&type->s_umount_key#107){++++}-{4:4}, at: super_lock+0x25c/0x3b0 fs/super.c:121
1 lock held by syz.0.3255/14980:
#0: ffff8880482d40e0 (&type->s_umount_key#107){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880482d40e0 (&type->s_umount_key#107){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
2 locks held by syz.9.3337/15194:
5 locks held by syz.5.3327/15202:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 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: 15202 Comm: syz.5.3327 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x1d/0xe0 lib/smp_processor_id.c:53
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 57 04 26 07 65 8b 0d 4c 04 26 07 f7 c1 ff ff ff 7f 74 0c 5b <41> 5e 41 5f 5d e9 14 f5 b5 f5 cc 9c 59 f7 c1 00 02 00 00 74 ea 65
RSP: 0018:ffffc900000072f8 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000101
RDX: 00000000a42637f2 RSI: ffffffff8d9779a6 RDI: ffffffff8bc08760
RBP: ffffffff8173fdd5 R08: ffffffff8173fdd5 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffffff81acf510 R12: 0000000000000002
R13: ffffffff8df41aa0 R14: 0000000000000000 R15: 0000000000000246
FS: 00007f10583106c0(0000) GS:ffff888125e1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000c038 CR3: 000000003a32f000 CR4: 0000000000350ef0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5870
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6781
kfree_skb_reason include/linux/skbuff.h:1322 [inline]
kfree_skb include/linux/skbuff.h:1331 [inline]
l2tp_ip_recv+0x890/0x13e0 net/l2tp/l2tp_ip.c:210
ip_protocol_deliver_rcu+0x2e0/0x440 net/ipv4/ip_input.c:207
ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6152 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6265
process_backlog+0x54f/0x1340 net/core/dev.c:6617
__napi_poll+0xae/0x320 net/core/dev.c:7681
napi_poll net/core/dev.c:7744 [inline]
net_rx_action+0x64a/0xe00 net/core/dev.c:7896
handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:936 [inline]
__dev_queue_xmit+0x1969/0x3100 net/core/dev.c:4859
dev_queue_xmit include/linux/netdevice.h:3381 [inline]
neigh_hh_output include/net/neighbour.h:540 [inline]
neigh_output include/net/neighbour.h:554 [inline]
ip_finish_output2+0xb52/0x1000 net/ipv4/ip_output.c:237
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x29f/0x450 net/ipv4/ip_output.c:438
ip_local_out net/ipv4/ip_output.c:131 [inline]
__ip_queue_xmit+0x118d/0x1c30 net/ipv4/ip_output.c:534
l2tp_ip_sendmsg+0x6c2/0x15f0 net/l2tp/l2tp_ip.c:520
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x19c/0x270 net/socket.c:742
____sys_sendmsg+0x52d/0x820 net/socket.c:2592
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
__sys_sendmmsg+0x227/0x430 net/socket.c:2735
__do_sys_sendmmsg net/socket.c:2762 [inline]
__se_sys_sendmmsg net/socket.c:2759 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2759
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f105738f749
Code: ff ff c3 66 2e 0f 1f 84 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 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1058310038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f10575e5fa0 RCX: 00007f105738f749
RDX: 00000000040000cf RSI: 0000200000000900 RDI: 0000000000000003
RBP: 00007f1057413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f10575e6038 R14: 00007f10575e5fa0 R15: 00007ffce5e2dcd8