rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 1, t=10502 jiffies, g=597341, q=28)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295293027-4295282525), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g597341 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:28688 pid: 14 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:4984 [inline]
__schedule+0xa9a/0x4940 kernel/sched/core.c:6265
schedule+0xd2/0x260 kernel/sched/core.c:6338
schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1966
rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2139
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 15916 Comm: syz-executor.2 Not tainted 5.15.0-rc7-next-20211029-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:458
print_other_cpu_stall kernel/rcu/tree_stall.h:563 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:706 [inline]
rcu_pending kernel/rcu/tree.c:3922 [inline]
rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2620
update_process_times+0x16d/0x200 kernel/time/timer.c:1785
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
__sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:strlen+0x4d/0x90 lib/string.c:487
Code: 07 38 d0 7f 04 84 c0 75 48 80 7d 00 00 74 39 48 bb 00 00 00 00 00 fc ff df 48 89 e8 48 83 c0 01 48 89 c2 48 89 c1 48 c1 ea 03 <83> e1 07 0f b6 14 1a 38 ca 7f 04 84 d2 75 1f 80 38 00 75 de 48 83
RSP: 0018:ffffc90011d07648 EFLAGS: 00000a03
RAX: ffffffff8a5d1a66 RBX: dffffc0000000000 RCX: ffffffff8a5d1a66
RDX: 1ffffffff14ba34c RSI: ffff88802103d0a8 RDI: ffffffff8a5d1a60
RBP: ffffffff8a5d1a60 R08: 0000000000000001 R09: 0000000000000001
R10: fffffbfff1a8d6c2 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff8b680d60 R14: ffff88802103d0a8 R15: ffffc90011d07728
strlen include/linux/fortify-string.h:102 [inline]
trace_event_get_offsets_lock_acquire include/trace/events/lock.h:13 [inline]
perf_trace_lock_acquire+0xbe/0x550 include/trace/events/lock.h:13
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x416/0x510 kernel/locking/lockdep.c:5608
__raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
_raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228
snd_seq_port_use_ptr+0x38/0x1a0 sound/core/seq/seq_ports.c:51
snd_seq_deliver_single_event.constprop.0+0x1ba/0x820 sound/core/seq/seq_clientmgr.c:617
snd_seq_deliver_event+0x4e7/0x970 sound/core/seq/seq_clientmgr.c:841
snd_seq_dispatch_event+0x112/0x580 sound/core/seq/seq_clientmgr.c:915
snd_seq_check_queue+0x18a/0x3f0 sound/core/seq/seq_queue.c:265
snd_seq_enqueue_event+0x1ed/0x3e0 sound/core/seq/seq_queue.c:334
snd_seq_client_enqueue_event.constprop.0+0x230/0x440 sound/core/seq/seq_clientmgr.c:976
snd_seq_write+0x388/0x690 sound/core/seq/seq_clientmgr.c:1096
vfs_write+0x28e/0xae0 fs/read_write.c:588
ksys_write+0x1ee/0x250 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f355c6dbae9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3559c51188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f355c7eef60 RCX: 00007f355c6dbae9
RDX: 00000000fffffee4 RSI: 00000000200000c0 RDI: 0000000000000004
RBP: 00007f355c735f25 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffce15117df R14: 00007f3559c51300 R15: 0000000000022000
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 38 d0 cmp %dl,%al
2: 7f 04 jg 0x8
4: 84 c0 test %al,%al
6: 75 48 jne 0x50
8: 80 7d 00 00 cmpb $0x0,0x0(%rbp)
c: 74 39 je 0x47
e: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx
15: fc ff df
18: 48 89 e8 mov %rbp,%rax
1b: 48 83 c0 01 add $0x1,%rax
1f: 48 89 c2 mov %rax,%rdx
22: 48 89 c1 mov %rax,%rcx
25: 48 c1 ea 03 shr $0x3,%rdx
* 29: 83 e1 07 and $0x7,%ecx <-- trapping instruction
2c: 0f b6 14 1a movzbl (%rdx,%rbx,1),%edx
30: 38 ca cmp %cl,%dl
32: 7f 04 jg 0x38
34: 84 d2 test %dl,%dl
36: 75 1f jne 0x57
38: 80 38 00 cmpb $0x0,(%rax)
3b: 75 de jne 0x1b
3d: 48 rex.W
3e: 83 .byte 0x83