INFO: task syz.5.1167:9546 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1167 state:D stack:25392 pid:9546 tgid:9543 ppid:6391 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5352 [inline]
__schedule+0x1665/0x5590 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7047 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7062
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119
rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114
__down_read_common kernel/locking/rwsem.c:1291 [inline]
__down_read kernel/locking/rwsem.c:1304 [inline]
down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570
mmap_read_lock include/linux/mmap_lock.h:592 [inline]
exit_mm+0x73/0x250 kernel/exit.c:557
do_exit+0x8b9/0x2490 kernel/exit.c:962
do_group_exit+0x21b/0x2d0 kernel/exit.c:1116
get_signal+0x1284/0x1330 kernel/signal.c:3036
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f904339c799
RSP: 002b:00007f9044247028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 00000000000023fd RBX: 00007f9043616090 RCX: 00007f904339c799
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f9043432c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9043616128 R14: 00007f9043616090 R15: 00007ffc2392dd48
INFO: task syz.5.1167:9552 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1167 state:D stack:24448 pid:9552 tgid:9543 ppid:6391 task_flags:0x40054c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5352 [inline]
__schedule+0x1665/0x5590 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7047 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7062
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119
rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114
__down_read_common kernel/locking/rwsem.c:1291 [inline]
__down_read kernel/locking/rwsem.c:1304 [inline]
down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570
mmap_read_lock include/linux/mmap_lock.h:592 [inline]
exit_mm+0x73/0x250 kernel/exit.c:557
do_exit+0x8b9/0x2490 kernel/exit.c:962
do_group_exit+0x21b/0x2d0 kernel/exit.c:1116
get_signal+0x1284/0x1330 kernel/signal.c:3036
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f904339c799
RSP: 002b:00007f90442050e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f9043616278 RCX: 00007f904339c799
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9043616278
RBP: 00007f9043616270 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9043616308 R14: 00007ffc2392dc60 R15: 00007ffc2392dd48
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by dhcpcd/5504:
#0: ffff88802c1d86e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267
#1: ffffffff8fbd4c00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8fbd4c00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826
2 locks held by getty/5600:
#0: ffff8880379d00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
6 locks held by kworker/0:3/5842:
#0: ffff888020ab7140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3260
#1: ffffc900047d7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3261
#2: ffff88802a2b11d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff88802a2b11d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff88802a2b61d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:995 [inline]
#3: ffff88802a2b61d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1068
#4: ffff88802aace1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff88802aace1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1068
#5: ffffffff8e5fa6e8 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214
4 locks held by udevd/6048:
#0: ffff8880b863ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#3: ffff88807ea41ca0 (&ep->wq){....}-{3:3}, at: __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124
4 locks held by kworker/u8:11/8028:
#0: ffff88801c2b6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3260
#1: ffffc9000552fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3261
#2: ffffffff8fbc5be8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
#3: ffffffff8e7637b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz.5.1167/9546:
#0: ffff88807c685ab8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline]
#0: ffff88807c685ab8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557
1 lock held by syz.5.1167/9552:
#0: ffff88807c685ab8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline]
#0: ffff88807c685ab8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557
2 locks held by syz.3.1498/10845:
#0: ffffffff8fbd4c00 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fbd4c00 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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:162 [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:353 [inline]
watchdog+0x1002/0x1060 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5843 Comm: kworker/0:4 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events dvb_usb_read_remote_control
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:752
Code: e8 9b 11 09 0a 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 90 97 1f 8e 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 fc 60 84 00 48 c7 c3 d8 d9 1f 93 49 03 1e 48 89
RSP: 0018:ffffc900000076c0 EFLAGS: 00000046
RAX: 1ffffffff1c3f2f2 RBX: 0000000000000000 RCX: 0000000000000103
RDX: 0000000000000000 RSI: ffffffff8c2871e0 RDI: ffffffff8c2871a0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000007878 R11: ffffffff81b1db20 R12: 0000000000000002
R13: ffffffff8e75d6a0 R14: ffffffff8e1f9790 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125436000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fada47e92f8 CR3: 000000007edb4000 CR4: 00000000003526f0
Call Trace:
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x57/0x2e0 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
insert_work+0x3d/0x330 kernel/workqueue.c:2202
__queue_work+0xd03/0x1020 kernel/workqueue.c:2357
call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1794 [inline]
__run_timers kernel/time/timer.c:2373 [inline]
__run_timer_base+0x67e/0x8b0 kernel/time/timer.c:2385
run_timer_base kernel/time/timer.c:2394 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
handle_softirqs+0x22a/0x870 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:739
irq_exit_rcu+0x9/0x30 kernel/softirq.c:756
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478
Code: 0f 84 44 ff ff ff e8 52 28 21 00 fb eb 44 e8 4a 28 21 00 e8 85 38 0f 0a 4d 85 f6 74 94 e8 3b 28 21 00 fb 48 c7 c7 e0 fa 74 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 3b 17
RSP: 0018:ffffc900047f7820 EFLAGS: 00000293
RAX: ffffffff81a58ae5 RBX: ffffffff81a5895f RCX: ffff8880795adb80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e74fae0
RBP: ffffc900047f78d0 R08: ffffffff90122ff7 R09: 1ffffffff20245fe
R10: dffffc0000000000 R11: fffffbfff20245ff R12: 0000000000000000
R13: 0000000000000027 R14: 0000000000000200 R15: 1ffff920008fef08
_printk+0xdd/0x130 kernel/printk/printk.c:2504
dvb_usb_generic_rw+0x37f/0x4d0 drivers/media/usb/dvb-usb/dvb-usb-urb.c:36
pctv452e_rc_query+0x137/0x670 drivers/media/usb/dvb-usb/pctv452e.c:589
dvb_usb_read_remote_control+0xb4/0x1a0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3288
process_scheduled_works kernel/workqueue.c:3379 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245