rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=dc5c/1/0x4000000000000000 softirq=38070/38071 fqs=146
rcu: 	(detected by 1, t=10502 jiffies, g=26809, q=14 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:mm_get_cid+0xab/0x130
Code: 41 5c 41 5d 41 5e 41 5f 5d e9 81 1a ca 09 cc 49 c7 c5 c8 f4 9a 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 <43> 0f b6 44 25 00 84 c0 75 41 44 8b 3d 3c 9f 08 0c 48 89 df 4c 89
RSP: 0018:ffffffff8dc07b88 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88812088c8d0 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff88812088c8d0
RBP: 0000000080000000 R08: ffff88812088c753 R09: 1ffff110241118ea
R10: dffffc0000000000 R11: ffffed10241118eb R12: dffffc0000000000
R13: 1ffffffff1b35e99 R14: 0000000080000000 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff88818e821000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f353cd0ffc8 CR3: 0000000113322000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __schedule+0x2140/0x4fd0
 schedule_idle+0x52/0x90
 do_idle+0x472/0x4d0
 cpu_startup_entry+0x44/0x60
 rest_init+0x2de/0x300
 start_kernel+0x381/0x3d0
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x143/0x1c0
 common_startup_64+0x13e/0x147
 </TASK>
rcu: rcu_preempt kthread starved for 10210 jiffies! g26809 f0x0 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:27480 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x149b/0x4fd0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x510/0xa50
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 5832 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 d4 95 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7f 91 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 63 91
RSP: 0000:ffffc90005427820 EFLAGS: 00000293
RAX: ffffffff81b5650d RBX: 1ffff1102420856d RCX: ffff8881740ed7c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005427950 R08: ffffffff8f822177 R09: 1ffffffff1f0442e
R10: dffffc0000000000 R11: fffffbfff1f0442f R12: ffff888121042b68
R13: dffffc0000000000 R14: ffff88823c63bb00 R15: 0000000000000000
FS:  000055555d8e9500(0000) GS:ffff8882a9e21000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555d9045c8 CR3: 0000000117b8e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x60a/0x1170
 ptep_clear_flush+0x120/0x170
 do_wp_page+0x1bb1/0x5810
 handle_mm_fault+0x14c5/0x32b0
 do_user_addr_fault+0xa7c/0x1380
 exc_page_fault+0x71/0xd0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f353bd4db0f
Code: 8d 34 19 48 39 d5 48 89 75 60 0f 95 c2 48 29 d8 48 83 c1 10 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 51 f8 <48> 89 46 08 eb 80 48 8d 0d 01 09 0f 00 48 8d 15 05 1b 0f 00 bf 01
RSP: 002b:00007fff1d183070 EFLAGS: 00010206
RAX: 0000000000006a41 RBX: 0000000000008040 RCX: 000055555d8fc590
RDX: 0000000000008041 RSI: 000055555d9045c0 RDI: 0000000000000004
RBP: 00007f353bfbacc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000802 R12: 0000000000008030
R13: 0000000000000076 R14: 00007f353bfbad20 R15: 0000000000000000
 </TASK>
