rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10506 jiffies, g=76269, q=208 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4295009356-4294998850), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g76269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=39973
rcu: rcu_preempt kthread starved for 10506 jiffies! g76269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->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 stack:26664 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 18272 Comm: syz.6.3363 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:rcu_is_watching+0x3a/0xb0
Code: e8 1b ff d3 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10 2d be 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 ac d0 7c 00 48 c7 c3 98 ff a1 92 49 03 1e 48 89
RSP: 0018:ffffc900001e07f8 EFLAGS: 00000046
RAX: 1ffffffff1b7c5a3 RBX: 0000000000000001 RCX: bc27f6ca38d34d00
RDX: 0000000000010000 RSI: ffffffff8be33e60 RDI: ffffffff8be33e20
RBP: ffffc900001e0918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: dffffc0000000000
R13: ffffffff81ada91e R14: ffffffff8dbe2d18 R15: dffffc0000000000
FS:  00007fda4b00e6c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000029c0 CR3: 000000010d3fc000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_release+0x4b/0x3e0
 _raw_spin_unlock_irqrestore+0x70/0x110
 hrtimer_try_to_cancel+0x3be/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:xas_start+0x6b6/0x770
Code: 00 00 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 b1 00 00 00 41 c6 06 01 48 c7 c7 61 48 a3 8d 48 c7 c2 c0 49 bb 8c e8 6a 64 25 f6 <48> 89 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 08 06 05 00 cc 44 89 e1
RSP: 0018:ffffc9000652fa08 EFLAGS: 00000246
RAX: ffffffff8b783303 RBX: ffff88812402f442 RCX: 0000000000080000
RDX: ffffc90021b54000 RSI: 0000000000000155 RDI: 0000000000000156
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8b78e010
R10: ffffc9000652faf0 R11: fffff52000ca5f61 R12: 0000000000000000
R13: ffffc9000652fae8 R14: 0000000000000010 R15: 1ffff92000ca5f5d
 xas_load+0x2c/0x5b0
 xa_load+0x118/0x210
 memcg_list_lru_alloc+0x12f/0x7e0
 __memcg_slab_post_alloc_hook+0x13c/0x7f0
 kmem_cache_alloc_lru_noprof+0x2c7/0x3d0
 sock_alloc_inode+0x28/0xc0
 alloc_inode+0x6a/0x1b0
 __sock_create+0x12d/0x9f0
 __sys_socketpair+0x1c5/0x560
 __x64_sys_socketpair+0x9b/0xb0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda4a18eba9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fda4b00e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007fda4a3d5fa0 RCX: 00007fda4a18eba9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001
RBP: 00007fda4a211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000029c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda4a3d6038 R14: 00007fda4a3d5fa0 R15: 00007ffeee77a558
 </TASK>
