INFO: task syz-executor:5827 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21592 pid:5827 tgid:5827 ppid:1 task_flags:0x400140 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
bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240
__wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52
out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:67
wait_on_bit include/linux/wait_bit.h:77 [inline]
gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1268
gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline]
__gfs2_lookup+0x117/0x270 fs/gfs2/inode.c:999
__lookup_slow+0x297/0x3d0 fs/namei.c:1866
lookup_slow+0x53/0x70 fs/namei.c:1883
walk_component fs/namei.c:2229 [inline]
lookup_last fs/namei.c:2730 [inline]
path_lookupat+0x3f5/0x8c0 fs/namei.c:2754
filename_lookup+0x212/0x570 fs/namei.c:2783
user_path_at+0x3a/0x60 fs/namei.c:3576
ksys_umount fs/namespace.c:2058 [inline]
__do_sys_umount fs/namespace.c:2066 [inline]
__se_sys_umount fs/namespace.c:2064 [inline]
__x64_sys_umount+0xee/0x160 fs/namespace.c:2064
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: 0033:0x7f7649190a77
RSP: 002b:00007ffe93141d58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f7649213d7d RCX: 00007f7649190a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe93141e10
RBP: 00007ffe93141e10 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe93142f00
R13: 00007f7649213d7d R14: 0000000000076566 R15: 00007ffe931450c0
Showing all locks held in the system:
3 locks held by kworker/1:0H/25:
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
1 lock held by klogd/5182:
2 locks held by dhcpcd/5488:
#0: ffff88807ce346f0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
#1: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826
2 locks held by getty/5582:
#0: ffff88814d1770a0 (&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
1 lock held by syz-executor/5809:
1 lock held by syz-executor/5827:
#0: ffff88805712eb48 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline]
#0: ffff88805712eb48 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1882
4 locks held by kworker/0:8/6018:
#0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000b1e7bc0 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000b1e7bc0 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888143efe280 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:333 [inline]
#2: ffff888143efe280 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_damage_work+0x110/0x740 drivers/gpu/drm/drm_fb_helper.c:372
#3: ffff88802416e128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x20/0x80 drivers/gpu/drm/drm_auth.c:435
6 locks held by kworker/u8:19/6158:
#0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90005007bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90005007bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8f304db0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670
#3: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1673
#4: ffff888066588788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6363 [inline]
#4: ffff888066588788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x123/0x6c0 net/mac80211/iface.c:2403
#5: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#5: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:956
1 lock held by syz-executor/8811:
1 lock held by syz-executor/9176:
#0: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
2 locks held by syz-executor/9178:
#0: ffffffff8ea6f288 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ea6f288 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8ea6f288 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
1 lock held by syz-executor/9387:
#0: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
2 locks held by dhcpcd/9416:
2 locks held by dhcpcd/9417:
#0: ffff888076de6f48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888076de6f48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff888076de6f48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
#1: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:956
3 locks held by syz.8.604/9423:
#0: ffffffff8df35980 (console_lock){+.+.}-{0:0}, at: do_fb_ioctl+0x583/0x750 drivers/video/fbdev/core/fb_chrdev.c:86
#1: ffff88802426e078 (&fb_info->lock){+.+.}-{4:4}, at: lock_fb_info include/linux/fb.h:623 [inline]
#1: ffff88802426e078 (&fb_info->lock){+.+.}-{4:4}, at: do_fb_ioctl+0x598/0x750 drivers/video/fbdev/core/fb_chrdev.c:87
#2: ffff888143efe280 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_setcmap+0x154/0x2c20 drivers/gpu/drm/drm_fb_helper.c:979
2 locks held by syz.2.605/9422:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
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:160 [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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25 Comm: kworker/1:0H Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_highpri snd_vmidi_output_work
RIP: 0010:__preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
RIP: 0010:sched_clock+0x1a/0x60 arch/x86/kernel/tsc.c:290
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 e8 d5 4f 58 00 65 ff 05 ae 67 17 11 e8 b9 ec f0 09 48 89 c3 <31> f6 65 ff 0d 9d 67 17 11 40 0f 94 c5 40 0f 94 c6 bf 02 00 00 00
RSP: 0018:ffffc900001f7690 EFLAGS: 00000002
RAX: 00000095e243c1b0 RBX: 00000095e243c1b0 RCX: 00000096e5f4c5a2
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff92864040
RBP: ffff88801c6f1e80 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003eec4 R12: 0000000000000002
R13: 0000000000000046 R14: ffff8880b863a918 R15: ffff88801c6f2a00
FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 000000005c70d000 CR4: 0000000000350ef0
Call Trace:
__lock_pin_lock kernel/locking/lockdep.c:5630 [inline]
lock_pin_lock+0xcb/0x150 kernel/locking/lockdep.c:5961
rq_pin_lock kernel/sched/sched.h:1806 [inline]
rq_lock kernel/sched/sched.h:1886 [inline]
__schedule+0x425/0x4fd0 kernel/sched/core.c:6768
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
class_spinlock_irqsave_destructor include/linux/spinlock.h:585 [inline]
snd_rawmidi_transmit+0xc9/0x100 sound/core/rawmidi.c:1493
snd_vmidi_output_work+0x1a3/0x410 sound/core/seq/seq_virmidi.c:151
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
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