rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=801c/1/0x4000000000000000 softirq=24594/24595 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=16389, q=132 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7840 Comm: syz.1.504 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:hrtimer_try_to_cancel+0x0/0x420
Code: ef e8 24 0e 76 00 e9 c4 fe ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 48 89 fb 49
RSP: 0018:ffffc90000006408 EFLAGS: 00000006
RAX: ffffffff81adabe1 RBX: ffff88811c398168 RCX: ffff88811da79cc0
RDX: 0000000000010100 RSI: 0000000000000004 RDI: ffff88811c398168
RBP: 00000000ffffffff R08: ffff88804b027a83 R09: 1ffff11009604f50
R10: dffffc0000000000 R11: ffffed1009604f51 R12: ffff88811c398210
R13: dffffc0000000000 R14: ffff88811c398168 R15: ffffffffffff41d5
FS:  00007f56b40996c0(0000) GS:ffff8880b8612000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 000000002783a000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 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+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 6f 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000006b58 EFLAGS: 00000206
RAX: 96c14210e8368900 RBX: 0000000000000000 RCX: 96c14210e8368900
RDX: 0000000000000000 RSI: ffffffff8dbaa0c3 RDI: ffffffff8be34280
RBP: ffffffff8172d195 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc90000006d18 R11: ffffffff81ac4d00 R12: 0000000000000002
R13: ffffffff8e13a120 R14: 0000000000000000 R15: 0000000000000246
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 __inet_inherit_port+0xd25/0x16f0
 tcp_v6_syn_recv_sock+0xfd9/0x1860
 tcp_check_req+0xf11/0x1800
 tcp_v6_rcv+0x16b9/0x2c30
 ip6_protocol_deliver_rcu+0xcb0/0x15c0
 ip6_input_finish+0x191/0x370
 NF_HOOK+0x30c/0x3a0
 ip6_input+0x16a/0x270
 NF_HOOK+0x30c/0x3a0
 __netif_receive_skb+0xd3/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 __dev_queue_xmit+0x1d79/0x3b50
 ip6_finish_output2+0x11bc/0x16a0
 ip6_xmit+0x107a/0x1840
 inet6_csk_xmit+0x473/0x720
 __tcp_transmit_skb+0x1db8/0x3680
 tcp_rcv_state_process+0x2a99/0x4140
 tcp_v6_do_rcv+0x89d/0x13f0
 __release_sock+0x1c5/0x350
 release_sock+0x5f/0x1f0
 mptcp_sendmsg_fastopen+0x1b3/0x580
 mptcp_sendmsg+0x176c/0x1970
 __sock_sendmsg+0xe5/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f56b318eba9
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:00007f56b4099038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f56b33d5fa0 RCX: 00007f56b318eba9
RDX: 0000000020000081 RSI: 0000200000000780 RDI: 000000000000000b
RBP: 00007f56b3211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f56b33d6038 R14: 00007f56b33d5fa0 R15: 00007ffcf1ebe6c8
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g16389 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:26920 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:
CPU: 1 UID: 0 PID: 7843 Comm: syz.2.503 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+0xd38/0x12d0
Code: 89 ee 83 e6 01 31 ff e8 b6 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5f 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 45 5f 0b 00 eb e4 44
RSP: 0018:ffffc90007aef480 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff11009608341 RCX: ffff88803fbc5640
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90007aef600 R08: ffff888023d73fc7 R09: 1ffff110047ae7f8
R10: dffffc0000000000 R11: ffffed10047ae7f9 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  00007f7133c576c0(0000) GS:ffff8881a3c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f75b3600d58 CR3: 0000000027ba4000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 exit_mmap+0x44c/0xb50
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7132d8eba9
Code: Unable to access opcode bytes at 0x7f7132d8eb7f.
RSP: 002b:00007f7133c570e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7132fd6098 RCX: 00007f7132d8eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7132fd6098
RBP: 00007f7132fd6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7132fd6128 R14: 00007ffecd3e18f0 R15: 00007ffecd3e19d8
 </TASK>
