INFO: task syz.4.6598:19623 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.4.6598 state:D stack:26744 pid:19623 tgid:19622 ppid:5606 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline]
rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578
nfsd_nl_svc_export_set_reqs_doit+0x132/0x1450 fs/nfsd/export.c:1057
genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x565/0x870 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2773
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0ed31bce59
RSP: 002b:00007f0ed1416028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0ed3435fa0 RCX: 00007f0ed31bce59
RDX: 0000000024000004 RSI: 0000200000000640 RDI: 0000000000000003
RBP: 00007f0ed3252e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0ed3436038 R14: 00007f0ed3435fa0 R15: 00007ffed84f8778
INFO: task syz.2.6669:19800 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.2.6669 state:D stack:27168 pid:19800 tgid:19799 ppid:5609 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline]
rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578
nfsd_nl_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1889
genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x565/0x870 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2773
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcb4661ce59
RSP: 002b:00007fcb4486e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fcb46895fa0 RCX: 00007fcb4661ce59
RDX: 00000000200080c4 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007fcb466b2e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcb46896038 R14: 00007fcb46895fa0 R15: 00007fff43717568
Showing all locks held in the system:
5 locks held by kworker/u8:0/12:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:4/66:
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000151fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000151fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
4 locks held by kworker/u8:6/214:
4 locks held by kworker/u8:7/496:
2 locks held by kworker/u8:12/1452:
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc90006997c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc90006997c40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
2 locks held by klogd/4953:
2 locks held by getty/5350:
#0: ffff888035c8c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
4 locks held by syz-executor/5585:
9 locks held by syz-executor/5605:
10 locks held by syz-executor/5607:
4 locks held by kworker/0:8/5873:
#0: ffff88801facb138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801facb138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc90005e57c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc90005e57c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffff888029d32210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#2: ffff888029d32210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899
#3: ffff88803dc84210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#3: ffff88803dc84210 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
4 locks held by udevd/8952:
#0: ffff88805b00b3d8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa5/0xcb0 fs/seq_file.c:183
#1: ffff88807e7ca878 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
#2: ffff8880723143c8 (kn->active#29){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff8880723143c8 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
#3: ffff88803dc84210 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1107 [inline]
#3: ffff88803dc84210 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by syz.3.6591/19609:
#0: ffffffff8f3df1a0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8e2e9138 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964
2 locks held by syz.4.6598/19623:
#0: ffffffff8f3df1a0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8e2e9138 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_set_reqs_doit+0x132/0x1450 fs/nfsd/export.c:1057
2 locks held by syz.2.6669/19800:
#0: ffffffff8f3df1a0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8e2e9138 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1889
2 locks held by kworker/0:2/20546:
2 locks held by syz.7.8162/23037:
#0: ffffffff8f3df1a0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8e2e9138 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x11a/0x6a0 fs/nfsd/nfsctl.c:2114
3 locks held by syz.6.8657/24093:
2 locks held by syz.5.8665/24109:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
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+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline]
RIP: 0010:__lock_acquire+0x18fa/0x2ce0 kernel/locking/lockdep.c:5237
Code: 13 25 ff 0f 00 00 39 05 c0 47 d7 11 73 06 89 05 b8 47 d7 11 48 8b 02 48 89 df 4c 39 e8 0f 84 34 fe ff ff 4c 89 78 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 20 fe ff ff 48 89 fb 48 c7 c7 b0 02 e9
RSP: 0018:ffffc90000157228 EFLAGS: 00000006
RAX: ffffffff9618c828 RBX: 00000000000003cd RCX: 0000000000000769
RDX: ffffffff95fb9ce8 RSI: ffff88801ceb8de8 RDI: 00000000000003cd
RBP: ada8b19c3d302271 R08: ffffc900001571f0 R09: 0000000000000020
R10: 0000000000000000 R11: ffffffff81a0f390 R12: 0000000000000768
R13: ffffffff931942c0 R14: ffff88801ceb8000 R15: ffffffff9606c088
FS: 0000000000000000(0000) GS:ffff88812611d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2baa75 CR3: 0000000037250000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73
ktime_expiry_to_cycles+0x4e/0x1e0 kernel/time/timekeeping.c:910
clockevent_set_next_coupled kernel/time/clockevents.c:314 [inline]
clockevents_program_event+0x199/0x630 kernel/time/clockevents.c:360
hrtimer_rearm kernel/time/hrtimer.c:2141 [inline]
__hrtimer_rearm_deferred+0x26f/0x430 kernel/time/hrtimer.c:2161
hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline]
hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline]
irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline]
irqentry_exit+0x8b7/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 51 1e 85 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 1b a9 cf 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c0 e7 88 09 cc 48 8d 3d b8 9a ed
RSP: 0018:ffffc90000157698 EFLAGS: 00000282
RAX: 78bb6fec895a6700 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000005df0ecf5 RSI: ffffffff8d89f46f RDI: ffffffff8ba92c80
RBP: ffffffff8187902c R08: ffffffff8187902c R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8de591e0 R12: 0000000000000002
R13: ffffffff8de591e0 R14: 0000000000000001 R15: 0000000000000246
__local_bh_disable_ip+0x5b/0x420 kernel/softirq.c:163
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:89 [inline]
hsr_check_duplicate+0x9e/0x1a0 net/hsr/hsr_framereg.c:598
hsr_forward_do net/hsr/hsr_forward.c:550 [inline]
hsr_forward_skb+0xe1c/0x28c0 net/hsr/hsr_forward.c:743
send_hsr_supervision_frame+0x761/0xd60 net/hsr/hsr_device.c:364
hsr_announce+0x1db/0x370 net/hsr/hsr_device.c:421
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x67b/0x9b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1151
smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245