rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=024c/1/0x4000000000000000 softirq=31418/31422 fqs=0
rcu: 	(t=10500 jiffies g=30277 q=670 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g30277 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=8396
rcu: rcu_preempt kthread starved for 10500 jiffies! g30277 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27544 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8053 Comm: syz.3.586 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:sched_mm_cid_fork+0x666/0x10e0
Code: 8e 26 8e 49 c1 ec 03 41 bd 00 00 00 80 eb 0a 89 e8 f7 d8 0f 81 09 fe ff ff f3 90 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 <84> c0 75 40 44 8b 35 d7 d3 91 0c 48 89 df 4c 89 f6 e8 44 69 1c 03
RSP: 0018:ffffc9000777fc48 EFLAGS: 00000887
RAX: 0000000000000000 RBX: ffff888173c66150 RCX: 0000000080000001
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff888173c66150
RBP: 0000000080000000 R08: 1ffff1102e78cad9 R09: 0000000000000000
R10: ffff888173c6580c R11: fffff52000eeff78 R12: 1ffffffff1c4d1d7
R13: 0000000080000000 R14: 0000000000000002 R15: ffff888173c655c0
FS:  00007f16c4eaf6c0(0000) GS:ffff88818dc90000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6ad18e69d3 CR3: 00000001afb28000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 bprm_execve+0xdb7/0x1440
 do_execveat_common+0x50d/0x690
 __x64_sys_execveat+0xc7/0xf0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f16c3f9cdd9
Code: ff c3 66 2e 0f 1f 84 00 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
RSP: 002b:00007f16c4eaf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f16c4215fa0 RCX: 00007f16c3f9cdd9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f16c4032d69 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f16c4216038 R14: 00007f16c4215fa0 R15: 00007ffcc1bd5bc8
 </TASK>
CPU: 1 UID: 0 PID: 8075 Comm: modprobe 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+0xfcf/0x13d0
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 fa fc 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 a5 f8 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 8a f8 0b
RSP: 0018:ffffc90006def680 EFLAGS: 00000293
RAX: ffffffff81b9abb6 RBX: ffff88823c63c2c8 RCX: ffff888169080000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90006def7c0 R08: ffffffff9030b1f7 R09: 1ffffffff206163e
R10: dffffc0000000000 R11: fffffbfff206163f R12: 1ffff110242085b9
R13: dffffc0000000000 R14: ffff888121042dc8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6ad18a3440 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x5c3/0x10b0
 tlb_flush_mmu+0x1a0/0xa10
 tlb_finish_mmu+0xf9/0x230
 free_ldt_pgtables+0x19d/0x350
 exit_mmap+0x1af/0x9e0
 __mmput+0x118/0x430
 exit_mm+0x18e/0x250
 do_exit+0x6a2/0x22c0
 do_group_exit+0x21b/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x221a/0x2240
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6ad1961a90
Code: Unable to access opcode bytes at 0x7f6ad1961a66.
RSP: 002b:00007ffd96c31a48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f6ad1a52860 RCX: 00007f6ad1961a90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001
RBP: 00007f6ad1a52860 R08: 00007ffd96c318c0 R09: 00007ffd96c319a0
R10: 00007ffd96c31900 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f6ad1a56658 R15: 0000000000000001
 </TASK>
