rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=104309, q=13)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295017524-4295007022), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g104309 f0x2 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:28696 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4955 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6236
 schedule+0xd3/0x270 kernel/sched/core.c:6315
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 24503 Comm: syz-executor.2 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481
 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:729 [inline]
 rcu_pending kernel/rcu/tree.c:3878 [inline]
 rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2597
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:read_pnet include/net/net_namespace.h:327 [inline]
RIP: 0010:sock_net include/net/sock.h:2603 [inline]
RIP: 0010:tcp_win_from_space include/net/tcp.h:1401 [inline]
RIP: 0010:__mptcp_space net/mptcp/protocol.h:315 [inline]
RIP: 0010:mptcp_cleanup_rbuf net/mptcp/protocol.c:489 [inline]
RIP: 0010:mptcp_recvmsg+0x7ee/0x27b0 net/mptcp/protocol.c:2027
Code: 00 00 4c 89 e0 48 c1 e8 03 42 0f b6 14 30 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 32 1e 00 00 41 8b 87 6c 08 00 00 <49> 8d 7f 30 01 c3 48 89 f8 48 c1 e8 03 44 29 eb 42 80 3c 30 00 0f
RSP: 0018:ffffc9000a61f738 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000020000 RCX: ffffffff88e98b97
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807e859988
RBP: ffff88807e859988 R08: 0000000000000000 R09: ffff88807e85998b
R10: ffffed100fd0b331 R11: 0000000000000000 R12: ffff88807e859fec
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88807e859780
 inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659
 sock_recvmsg_nosec net/socket.c:944 [inline]
 ____sys_recvmsg+0x527/0x600 net/socket.c:2626
 ___sys_recvmsg+0x127/0x200 net/socket.c:2670
 do_recvmmsg+0x24d/0x6d0 net/socket.c:2764
 __sys_recvmmsg net/socket.c:2843 [inline]
 __do_sys_recvmmsg net/socket.c:2866 [inline]
 __se_sys_recvmmsg net/socket.c:2859 [inline]
 __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe349bf1739
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe347168188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fe349cf5f80 RCX: 00007fe349bf1739
RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003
RBP: 00007fe349c4bcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000246 R12: 00007fe349cf5f80
R13: 00007ffd6215a69f R14: 00007fe347168300 R15: 0000000000022000
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	4c 89 e0             	mov    %r12,%rax
   5:	48 c1 e8 03          	shr    $0x3,%rax
   9:	42 0f b6 14 30       	movzbl (%rax,%r14,1),%edx
   e:	4c 89 e0             	mov    %r12,%rax
  11:	83 e0 07             	and    $0x7,%eax
  14:	83 c0 03             	add    $0x3,%eax
  17:	38 d0                	cmp    %dl,%al
  19:	7c 08                	jl     0x23
  1b:	84 d2                	test   %dl,%dl
  1d:	0f 85 32 1e 00 00    	jne    0x1e55
  23:	41 8b 87 6c 08 00 00 	mov    0x86c(%r15),%eax
* 2a:	49 8d 7f 30          	lea    0x30(%r15),%rdi <-- trapping instruction
  2e:	01 c3                	add    %eax,%ebx
  30:	48 89 f8             	mov    %rdi,%rax
  33:	48 c1 e8 03          	shr    $0x3,%rax
  37:	44 29 eb             	sub    %r13d,%ebx
  3a:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1)
  3f:	0f                   	.byte 0xf