rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=7ff4/1/0x4000000000000000 softirq=55475/58964 fqs=0
rcu: 	(t=10500 jiffies g=47709 q=232 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g47709 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=17574
rcu: rcu_preempt kthread starved for 10500 jiffies! g47709 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27816 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x1550/0x5060
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x1560
 rcu_gp_kthread+0x9d/0x3b0
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 ret_from_fork_asm+0x1a/0x30
 </TASK>
CPU: 0 UID: 0 PID: 5839 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+0xce7/0x12d0
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 a2 b7 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 4d b3 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 31 b3
RSP: 0018:ffffc90004db7560 EFLAGS: 00000293
RAX: ffffffff81b79a3f RBX: 1ffff110478c8129 RCX: ffff888101b01d40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004db76e0 R08: ffffffff8fc25577 R09: 1ffffffff1f84aae
R10: dffffc0000000000 R11: fffffbfff1f84aaf R12: ffff88823c640948
R13: dffffc0000000000 R14: ffff88812103bb00 R15: 0000000000000001
FS:  00005555768bc500(0000) GS:ffff88818e41f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c352225 CR3: 000000011c418000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x699/0x1260
 dup_mmap+0x1620/0x1bb0
 copy_mm+0x13b/0x4b0
 copy_process+0x166e/0x3980
 kernel_clone+0x248/0x870
 __x64_sys_clone+0x1b6/0x230
 do_syscall_64+0xf0/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f379f5c3752
Code: 89 e7 e8 f1 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffe9e2024c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe9e2024c0 RCX: 00007f379f5c3752
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffe9e20264c R08: 0000000000000000 R09: 0000000000000001
R10: 00005555768bc7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000399fb R15: 00007ffe9e2026a0
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16053 Comm: syz.2.2983 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+0xb1/0x130
Code: 41 5f 5d c3 cc cc cc cc cc 49 c7 c5 c8 34 c6 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 2c 4c 32 0c 48 89 df 4c 89 fe e8 79 cf 04 03
RSP: 0018:ffffc90007b57788 EFLAGS: 00000887
RAX: 0000000000000000 RBX: ffff8881bad9b050 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8881bad9b050
RBP: 0000000080000000 R08: ffff8881bad9aed3 R09: 1ffff110375b35da
R10: dffffc0000000000 R11: ffffed10375b35db R12: dffffc0000000000
R13: 1ffffffff1b8c699 R14: 0000000080000000 R15: 0000000000000002
FS:  00007f13ef00b6c0(0000) GS:ffff8882a9a1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1459b86100 CR3: 000000016f5be000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __schedule+0x222f/0x5060
 schedule+0x164/0x360
 __futex_wait+0x1ee/0x420
 futex_wait+0x119/0x380
 do_futex+0x333/0x420
 __se_sys_futex+0x3a8/0x450
 do_syscall_64+0xf0/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f13ee19acb9
Code: Unable to access opcode bytes at 0x7f13ee19ac8f.
RSP: 002b:00007f13ef00b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f13ee415fa8 RCX: 00007f13ee19acb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f13ee415fa8
RBP: 00007f13ee415fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f13ee416038 R14: 00007fffd34435a0 R15: 00007fffd3443688
 </TASK>
