INFO: task syz.4.1254:18763 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1254 state:D stack:22280 pid:18763 tgid:18761 ppid:5816 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
do_fchownat+0x134/0x270 fs/open.c:816
__do_sys_chown fs/open.c:839 [inline]
__se_sys_chown fs/open.c:837 [inline]
__x64_sys_chown+0x82/0xa0 fs/open.c:837
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b113af749
RSP: 002b:00007f8b0f616038 EFLAGS: 00000246 ORIG_RAX: 000000000000005c
RAX: ffffffffffffffda RBX: 00007f8b11605fa0 RCX: 00007f8b113af749
RDX: 000000000000000a RSI: 000000003a736e6f RDI: 0000200000000080
RBP: 00007f8b11433f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b11606038 R14: 00007f8b11605fa0 R15: 00007ffe6cad6ad8
INFO: task syz.4.1254:18767 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1254 state:D stack:25704 pid:18767 tgid:18761 ppid:5816 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
do_unlinkat+0x133/0x570 fs/namei.c:5416
__do_sys_unlinkat fs/namei.c:5469 [inline]
__se_sys_unlinkat fs/namei.c:5462 [inline]
__x64_sys_unlinkat+0xd3/0xf0 fs/namei.c:5462
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b113af749
RSP: 002b:00007f8b0f5f5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f8b11606090 RCX: 00007f8b113af749
RDX: 0000000000000000 RSI: 0000200000000380 RDI: ffffffffffffff9c
RBP: 00007f8b11433f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b11606128 R14: 00007f8b11606090 R15: 00007ffe6cad6ad8
INFO: task syz.4.1254:18769 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1254 state:D stack:26840 pid:18769 tgid:18761 ppid:5816 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
do_fchownat+0x134/0x270 fs/open.c:816
__do_sys_lchown fs/open.c:844 [inline]
__se_sys_lchown fs/open.c:842 [inline]
__x64_sys_lchown+0x85/0xa0 fs/open.c:842
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b113af749
RSP: 002b:00007f8b0f5d4038 EFLAGS: 00000246 ORIG_RAX: 000000000000005e
RAX: ffffffffffffffda RBX: 00007f8b11606180 RCX: 00007f8b113af749
RDX: 000000000000000a RSI: 0000000000008000 RDI: 0000200000000480
RBP: 00007f8b11433f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b11606218 R14: 00007f8b11606180 R15: 00007ffe6cad6ad8
Showing all locks held in the system:
5 locks held by kworker/u8:0/12:
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90000117b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000117b80 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e898600 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670
#3: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x9e0 net/core/dev.c:13022
#4: ffff88804eb2ae98 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2781 [inline]
#4: ffff88804eb2ae98 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
#4: ffff88804eb2ae98 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1198/0x2330 net/core/dev.c:12368
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:16/3754:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000ccb7b80 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000ccb7b80 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
3 locks held by udevd/5171:
2 locks held by dhcpcd/5465:
#0: ffffffff8e889798 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5f1/0x790 net/socket.c:1337
#1: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:579
2 locks held by getty/5566:
#0: ffff8880348450a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
1 lock held by udevd/5865:
#0: ffff888148c66ea8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline]
#0: ffff888148c66ea8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:855
1 lock held by syz-executor/6843:
#0: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436
1 lock held by syz.4.1254/18763:
#0: ffff88804eb54480 (sb_writers#31){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
1 lock held by syz.4.1254/18767:
#0: ffff88804eb54480 (sb_writers#31){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
1 lock held by syz.4.1254/18769:
#0: ffff88804eb54480 (sb_writers#31){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
2 locks held by syz-executor/19958:
#0: ffffffff8edd0628 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8edd0628 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8edd0628 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
3 locks held by kworker/1:3/19967:
#0: ffff88813ff56138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff56138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9001df2fb80 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9001df2fb80 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xa1/0xf00 net/wireless/reg.c:2453
3 locks held by kworker/u8:30/20144:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000484fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000484fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e8a5738 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by syz.3.1528/20585:
3 locks held by syz.8.1531/20587:
6 locks held by syz.6.1534/20590:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 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+0x599/0xb30 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: 5171 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0x274/0x2cf0 kernel/locking/lockdep.c:-1
Code: e8 61 9b 1a 03 4d 89 f1 48 8b 74 24 18 44 8b 74 24 20 48 83 bc 24 20 01 00 00 00 0f 85 ce fe ff ff 44 89 74 24 20 44 89 3c 24 <8b> bc 24 38 01 00 00 4c 8b 84 24 28 01 00 00 4c 8b 74 24 08 4d 8d
RSP: 0018:ffffc90003eb75b8 EFLAGS: 00000046
RAX: 0000000000000113 RBX: 0000000000000000 RCX: ffffffff925a9390
RDX: 0000000000000001 RSI: 000000000000000b RDI: ffffffff8d5ae8c0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8d5ae8c0
R10: 0000000000000000 R11: fffffbfff1db666f R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fb7d9d7c880(0000) GS:ffff888126d01000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2a82ae CR3: 0000000036cdc000 CR4: 00000000003526f0
Call Trace:
reacquire_held_locks+0x121/0x1c0 kernel/locking/lockdep.c:5385
__lock_release kernel/locking/lockdep.c:5574 [inline]
lock_release+0x1ab/0x3b0 kernel/locking/lockdep.c:5889
rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
spin_unlock include/linux/spinlock_rt.h:105 [inline]
d_alloc_parallel+0x2ec/0x1610 fs/dcache.c:2607
__lookup_slow+0x11c/0x3d0 fs/namei.c:1843
lookup_slow+0x53/0x70 fs/namei.c:1875
walk_component fs/namei.c:2221 [inline]
lookup_last fs/namei.c:2722 [inline]
path_lookupat+0x3f5/0x8c0 fs/namei.c:2746
filename_lookup+0x212/0x570 fs/namei.c:2775
do_readlinkat+0xd9/0x500 fs/stat.c:576
__do_sys_readlink fs/stat.c:613 [inline]
__se_sys_readlink fs/stat.c:610 [inline]
__x64_sys_readlink+0x7f/0x90 fs/stat.c:610
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb7d9ed83a7
Code: 00 00 90 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 00 31 c9 e8 8a 20 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 ba 0d 00 f7 d8 64 89 02 48
RSP: 002b:00007ffe740bc4e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffe740bc6f0 RCX: 00007fb7d9ed83a7
RDX: 0000000000000200 RSI: 00007ffe740bc4f0 RDI: 00007ffe740bc6f0
RBP: 000055acafdda910 R08: 0000000000000064 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffe740bc4f0
R13: 000055aca8a31100 R14: 0000000000000001 R15: 00007ffe740bcd10