rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P15870/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=79669, q=101940 ncpus=2)
task:syz.2.4199      state:R  running task     stack:24664 pid:15870 tgid:15869 ppid:5728   task_flags:0x40054c flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 preempt_schedule_common+0x82/0xd0
 preempt_schedule_thunk+0x16/0x30
 _raw_spin_unlock+0x3f/0x50
 __zap_vma_range+0x3d11/0x4b40
 unmap_vmas+0x379/0x530
 exit_mmap+0x280/0x9e0
 __mmput+0x118/0x430
 exit_mm+0x18e/0x250
 do_exit+0x6a2/0x22c0
 do_group_exit+0x21b/0x2d0
 get_signal+0x1284/0x1330
 arch_do_signal_or_restart+0xbc/0x830
 exit_to_user_mode_loop+0x86/0x480
 do_syscall_64+0x33e/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98c179cdd9
RSP: 002b:00007f98c2580028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: 000000000000000b RBX: 00007f98c1a15fa0 RCX: 00007f98c179cdd9
RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f98c1832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98c1a16038 R14: 00007f98c1a15fa0 R15: 00007ffd306891a8
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 15870 Comm: syz.2.4199 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:__sanitizer_cov_trace_const_cmp8+0x2e/0x90
Code: 48 8b 04 24 65 48 8b 0d d8 46 73 11 65 8b 15 f9 46 73 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 cc 16 00 00 00 <74> 4e 8b 91 a8 16 00 00 83 fa 03 75 43 48 8b 91 b0 16 00 00 44 8b
RSP: 0000:ffffc90000a078d8 EFLAGS: 00000246
RAX: ffffffff897ad34b RBX: 0000000000000004 RCX: ffff88811526d880
RDX: 0000000000000100 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc90000a07f18 R08: ffffffff897ac4f1 R09: ffffffff8e95cda0
R10: ffffc90000a07fa0 R11: fffff52000140ffb R12: 0000000000000000
R13: 0000000000000004 R14: ffff88804226cd80 R15: ffffffff8e289678
FS:  00007f98c25806c0(0000) GS:ffff8882a9291000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32d11ff8 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __skb_flow_dissect+0x123b/0x6e80
 __xfrm_decode_session+0xf3/0xbb0
 ip_route_me_harder+0x9c0/0xf90
 synproxy_send_tcp+0x34c/0x670
 synproxy_send_client_synack+0x8c1/0xe30
 nft_synproxy_eval_v4+0x34a/0x4e0
 nft_synproxy_do_eval+0x305/0x580
 nft_do_chain+0x467/0x19f0
 nft_do_chain_inet+0x360/0x4b0
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x21f/0x3c0
 NF_HOOK+0x336/0x3c0
 process_backlog+0xaa3/0x1950
 __napi_poll+0xae/0x340
 net_rx_action+0x627/0xf70
 handle_softirqs+0x22a/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__schedule+0x17d2/0x5680
Code: 23 4c 89 ef 4c 89 e6 e8 fc 29 8a f5 48 89 c7 e8 84 c9 eb f5 31 ff 4d 39 e5 40 0f 95 c7 e8 66 d5 eb f5 48 8b 84 24 00 01 00 00 <66> 42 c7 44 30 0c f8 f8 48 c7 84 24 40 01 00 00 0e 36 e0 45 4a c7
RSP: 0000:ffffc90003aa74a0 EFLAGS: 00000202
RAX: 1ffff92000754ebc RBX: ffff88823c63b018 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c28b4c0 RDI: ffffffff8c28b480
RBP: ffffc90003aa76c0 R08: ffffffff9030b2f7 R09: 1ffffffff206165e
R10: dffffc0000000000 R11: fffffbfff206165f R12: ffff8881bf871d80
R13: ffff88811526d880 R14: dffffc0000000000 R15: 1ffff110478c776c
 preempt_schedule_irq+0x4d/0xa0
 irqentry_exit+0x14f/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__update_page_owner_free_handle+0x455/0x470
Code: c7 c7 c0 56 dd 8b be 64 03 00 00 48 c7 c2 c0 58 dd 8b e8 4e fc 66 ff 48 c7 c7 a0 cd 95 8e 4c 89 f6 e8 cf e2 66 ff 48 83 c4 40 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 5c 90 70 ff 66 66 66 2e 0f 1f 84
RSP: 0000:ffffc90003aa77f8 EFLAGS: 00000282
RAX: 60cd58c6d3d0ef00 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8e21c286 RDI: ffffffff8c28b4e0
RBP: ffff8881629cc814 R08: ffff8881629cc7d7 R09: 1ffff1102c5398fa
R10: dffffc0000000000 R11: ffffed102c5398fb R12: 00000000001adc1a
R13: 0000000000000001 R14: ffffffff823ae82e R15: ffff8881629cc820
 __reset_page_owner+0x85/0x1f0
 free_pages_prepare+0x936/0xaa0
 __free_contig_range_common+0x174/0x340
 free_pages_bulk+0x48/0x120
 vfree+0x254/0x320
 kcov_close+0x28/0x50
 __fput+0x44f/0xa60
 task_work_run+0x1d9/0x270
 do_exit+0x70f/0x22c0
 do_group_exit+0x21b/0x2d0
 get_signal+0x1284/0x1330
 arch_do_signal_or_restart+0xbc/0x830
 exit_to_user_mode_loop+0x86/0x480
 do_syscall_64+0x33e/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98c179cdd9
Code: Unable to access opcode bytes at 0x7f98c179cdaf.
RSP: 002b:00007f98c2580028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: 000000000000000b RBX: 00007f98c1a15fa0 RCX: 00007f98c179cdd9
RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f98c1832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98c1a16038 R14: 00007f98c1a15fa0 R15: 00007ffd306891a8
 </TASK>
