Kernel bug: BUG: unable to handle kernel paging request in ip_route_output_key_hash_rcu
Subsystem: net
Status: fixed

Crash report:
BUG: unable to handle page fault for address: ffffed101acc9400
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 17fff6067 P4D 17fff6067 PUD 7ffd6067 PMD 0 
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 6079 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__mkroute_output net/ipv4/route.c:2649 [inline]
RIP: 0010:ip_route_output_key_hash_rcu+0x6c0/0x2870 net/ipv4/route.c:2875
Code: 24 30 48 85 ed 0f 84 91 14 00 00 e8 5a 69 1b f8 48 83 c5 30 e8 51 69 1b f8 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 06 1e 00 00 48 8b 6d 00 e8 3d 39 a2 01 31 ff 41
RSP: 0018:ffffc900059d6ca8 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffc900059d6ef8 RCX: ffffffff89ed4ad2
RDX: 1ffff1101acc9400 RSI: ffffffff89ed360f RDI: ffff88802c665658
RBP: ffff8880d664a000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88802c665620
R13: ffff88803a439c00 R14: ffffc900059d6d58 R15: ffff88803230a000
FS:  000055558dc94500(0000) GS:ffff8880d664a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed101acc9400 CR3: 000000002ca2a000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ip_route_output_key_hash+0x118/0x2b0 net/ipv4/route.c:2705
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2932
 ip_route_output_key include/net/route.h:179 [inline]
 sctp_v4_get_dst+0x3c4/0x1220 net/sctp/protocol.c:455
 sctp_transport_route+0x131/0x360 net/sctp/transport.c:448
 sctp_ootb_pkt_new+0x24c/0x440 net/sctp/sm_statefuns.c:6437
 sctp_sf_abort_violation+0x792/0xcf0 net/sctp/sm_statefuns.c:4771
 sctp_sf_violation_chunklen net/sctp/sm_statefuns.c:4830 [inline]
 sctp_sf_ootb+0x45c/0x870 net/sctp/sm_statefuns.c:3721
 sctp_do_sm+0x17a/0x5be0 net/sctp/sm_sideeffect.c:1172
 sctp_endpoint_bh_rcv+0x43f/0x880 net/sctp/endpointola.c:408
 sctp_inq_push+0x1db/0x280 net/sctp/inqueue.c:88
 sctp_rcv+0x13e1/0x3c30 net/sctp/input.c:243
 ip_protocol_deliver_rcu+0x44c/0x4d0 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3f2/0x6e0 net/ipv4/ip_input.c:241
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_local_deliver+0x19a/0x1f0 net/ipv4/ip_input.c:262
 dst_input include/net/dst.h:480 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_rcv+0x2d9/0x5d0 net/ipv4/ip_input.c:573
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6156
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6269
 netif_receive_skb_internal net/core/dev.c:6355 [inline]
 netif_receive_skb+0x139/0x820 net/core/dev.c:6414
 tun_rx_batched.isra.0+0x3f6/0x750 drivers/net/tun.c:1509
 tun_get_user+0x1e2e/0x3e10 drivers/net/tun.c:1953
 tun_chr_write_iter+0xdc/0x200 drivers/net/tun.c:1999
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:688
 ksys_write+0x12a/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2a9979c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffec6c44e78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2a99a15fa0 RCX: 00007f2a9979c629
RDX: 000000000000004e RSI: 0000200000000280 RDI: 0000000000000004
RBP: 00007f2a99832b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2a99a15fac R14: 00007f2a99a15fa0 R15: 00007f2a99a15fa0
 </TASK>
Modules linked in:
CR2: ffffed101acc9400
---[ end trace 0000000000000000 ]---
RIP: 0010:__mkroute_output net/ipv4/route.c:2649 [inline]
RIP: 0010:ip_route_output_key_hash_rcu+0x6c0/0x2870 net/ipv4/route.c:2875
Code: 24 30 48 85 ed 0f 84 91 14 00 00 e8 5a 69 1b f8 48 83 c5 30 e8 51 69 1b f8 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 06 1e 00 00 48 8b 6d 00 e8 3d 39 a2 01 31 ff 41
RSP: 0018:ffffc900059d6ca8 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffc900059d6ef8 RCX: ffffffff89ed4ad2
RDX: 1ffff1101acc9400 RSI: ffffffff89ed360f RDI: ffff88802c665658
RBP: ffff8880d664a000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88802c665620
R13: ffff88803a439c00 R14: ffffc900059d6d58 R15: ffff88803230a000
FS:  000055558dc94500(0000) GS:ffff8880d664a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed101acc9400 CR3: 000000002ca2a000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	24 30                	and    $0x30,%al
   2:	48 85 ed             	test   %rbp,%rbp
   5:	0f 84 91 14 00 00    	je     0x149c
   b:	e8 5a 69 1b f8       	call   0xf81b696a
  10:	48 83 c5 30          	add    $0x30,%rbp
  14:	e8 51 69 1b f8       	call   0xf81b696a
  19:	48 89 ea             	mov    %rbp,%rdx
  1c:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  23:	fc ff df
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 06 1e 00 00    	jne    0x1e3a
  34:	48 8b 6d 00          	mov    0x0(%rbp),%rbp
  38:	e8 3d 39 a2 01       	call   0x1a2397a
  3d:	31 ff                	xor    %edi,%edi
  3f:	41                   	rex.B