rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (2 ticks this GP) idle=720c/1/0x4000000000000000 softirq=190823/190823 fqs=2
rcu: 	(detected by 0, t=10502 jiffies, g=202985, q=583 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 537 Comm: syz.6.9829 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_is_watching+0x10/0xb0
Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 e0 38 8e 11 <e8> eb 78 fd 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df
RSP: 0018:ffffc90000a08bc0 EFLAGS: 00000082
RAX: ffffffff81b275b1 RBX: 0000000000000001 RCX: 0000000000010100
RDX: ffff88801c451d80 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffff88810be53300 R08: ffffffff9030b1f7 R09: 1ffffffff206163e
R10: dffffc0000000000 R11: fffffbfff206163f R12: 0000000000000001
R13: 1ffff110478c507a R14: ffff88823c628420 R15: ffffffff89b84aa0
FS:  00007f229c8d56c0(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000100 CR3: 00000000241ee000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __hrtimer_run_queues+0x32a/0xa20
 hrtimer_interrupt+0x44b/0x950
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__rcu_read_lock+0x0/0x60
Code: 3f fc ff ff 4c 89 ff e8 5e 82 85 00 e9 32 fc ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 53 65 48 8b 1d ab 83 8d 11 48 81 c3 c4 04 00 00 48 89
RSP: 0018:ffffc90000a08ec8 EFLAGS: 00000202
RAX: 00000000000569f2 RBX: 1ffff110478c7977 RCX: 0000000080000100
RDX: 0000000000000002 RSI: ffffffff8dfa8792 RDI: ffffffff8c28b5e0
RBP: 0000000000000001 R08: ffffffff9030b1f7 R09: 1ffffffff206163e
R10: dffffc0000000000 R11: fffffbfff206163f R12: ffff88823c63cbc0
R13: 0000000000000002 R14: ffff88823c63cbb8 R15: ffff88810be53000
 net_tx_action+0x5af/0xc30
 handle_softirqs+0x22a/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x90
Code: 89 44 11 20 e9 d9 70 e5 09 cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d d8 56 73 11 65 8b 15 f9 56 73 11 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90003b16860 EFLAGS: 00000246
RAX: ffffffff820e3d8c RBX: ffffea0006a5bac0 RCX: ffff88801c451d80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffea0006a5bac7 R09: 1ffffd4000d4b758
R10: dffffc0000000000 R11: fffff94000d4b759 R12: 0000000000001000
R13: 0000000000001000 R14: 0000000000000000 R15: ffffea0006a5bac8
 shmem_write_end+0x3fc/0x5d0
 generic_perform_write+0x620/0x8f0
 shmem_file_write_iter+0xf8/0x120
 __kernel_write_iter+0x41e/0x880
 dump_user_range+0xc19/0x12c0
 elf_core_dump+0x34c2/0x3ad0
 coredump_write+0x1216/0x1910
 vfs_coredump+0x3807/0x4530
 get_signal+0x1107/0x1330
 arch_do_signal_or_restart+0xbc/0x830
 irqentry_exit+0x284/0x730
 exc_general_protection+0x16b/0x1f0
 asm_exc_general_protection+0x26/0x30
RIP: 0033:0x7f229b99cde1
Code: 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:0000200000000280 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f229bc15fa0 RCX: 00007f229b99cdd9
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000120000
RBP: 00007f229ba32d69 R08: 0000200000000440 R09: 0000200000000440
R10: 0000200000000300 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f229bc16038 R14: 00007f229bc15fa0 R15: 00007ffc5bed5e78
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g202985 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27536 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 26 Comm: kworker/u9:0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_pc+0x30/0x70
Code: 04 24 65 48 8b 0d b8 5b 73 11 65 8b 15 d9 5b 73 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 cc 16 00 00 00 74 2c <8b> 91 a8 16 00 00 83 fa 02 75 21 48 8b 91 b0 16 00 00 48 8b 32 48
RSP: 0018:ffffc90000a176f8 EFLAGS: 00000246
RAX: ffffffff81b9abb6 RBX: ffff88812103c2c8 RCX: ffff8881032dd880
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000a17840 R08: ffffffff9030b1f7 R09: 1ffffffff206163e
R10: dffffc0000000000 R11: fffffbfff206163f R12: 1ffff110478c8199
R13: dffffc0000000000 R14: ffff88823c640cc8 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88818dc90000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000015bffc CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 smp_call_function_many_cond+0xfe6/0x13d0
 on_each_cpu_cond_mask+0x3f/0x80
 smp_text_poke_batch_finish+0x5f5/0x1160
 arch_jump_label_transform_apply+0x1c/0x30
 static_key_enable_cpuslocked+0x128/0x240
 static_key_enable+0x1a/0x20
 toggle_allocation_gate+0xab/0x290
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
