syzbot

BUG: unable to handle page fault for address: ffffed1011ae5e00
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 5ffcd067 P4D 5ffcd067 PUD 2fff7067 PMD 0 
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5500 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~bpo12+1 04/01/2014
RIP: 0010:__mkroute_output net/ipv4/route.c:2649 [inline]
RIP: 0010:ip_route_output_key_hash_rcu+0x12fc/0x23e0 net/ipv4/route.c:2875
Code: 4c 8b 35 2f ea bc 08 49 83 c7 38 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 ce 38 75 f8 4d 03 37 4c 89 f0 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 f7 e8 b6 38 75 f8 4d 8b 36 e8 9e 72 96 01
RSP: 0018:ffffc9000298e948 EFLAGS: 00010a06
RAX: 1ffff11011ae5e00 RBX: 0000000080000000 RCX: ffff888000bdc900
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffff888000bdc900 R09: 0000000000000003
R10: 0000000000000005 R11: 0000000000000000 R12: ffffc9000298ebd3
R13: 0000000000000000 R14: ffff88808d72f000 R15: ffff888036590158
FS:  000055556855e500(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed1011ae5e00 CR3: 0000000042bac000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ip_route_output_key_hash+0x174/0x280 net/ipv4/route.c:2705
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2932
 ip_route_output_key include/net/route.h:179 [inline]
 sctp_v4_get_dst+0x3c7/0x1200 net/sctp/protocol.c:455
 sctp_transport_route+0x118/0x2f0 net/sctp/transport.c:448
 sctp_ootb_pkt_new+0x28b/0x3c0 net/sctp/sm_statefuns.c:6437
 sctp_sf_abort_violation+0x14b/0xc60 net/sctp/sm_statefuns.c:4771
 sctp_sf_violation_chunklen net/sctp/sm_statefuns.c:4830 [inline]
 sctp_sf_ootb+0x4df/0x7c0 net/sctp/sm_statefuns.c:-1
 sctp_do_sm+0x1e7/0x5a20 net/sctp/sm_sideeffect.c:1172
 sctp_endpoint_bh_rcv+0x591/0x7e0 net/sctp/endpointola.c:408
 sctp_rcv+0x11dc/0x1870 net/sctp/input.c:243
 ip_protocol_deliver_rcu+0x2e0/0x440 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
 __netif_receive_skb_one_core net/core/dev.c:6079 [inline]
 __netif_receive_skb+0x143/0x380 net/core/dev.c:6192
 netif_receive_skb_internal net/core/dev.c:6278 [inline]
 netif_receive_skb+0x1cb/0x790 net/core/dev.c:6337
 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485
 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953
 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd9ab8e1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007ffca504fd10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbd9ade5fa0 RCX: 00007fbd9ab8e1ff
RDX: 0000000000000032 RSI: 00002000000000c0 RDI: 00000000000000c8
RBP: 00007fbd9ac13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000032 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fbd9ade5fa0 R14: 00007fbd9ade5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
CR2: ffffed1011ae5e00
---[ end trace 0000000000000000 ]---
RIP: 0010:__mkroute_output net/ipv4/route.c:2649 [inline]
RIP: 0010:ip_route_output_key_hash_rcu+0x12fc/0x23e0 net/ipv4/route.c:2875
Code: 4c 8b 35 2f ea bc 08 49 83 c7 38 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 ce 38 75 f8 4d 03 37 4c 89 f0 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 f7 e8 b6 38 75 f8 4d 8b 36 e8 9e 72 96 01
RSP: 0018:ffffc9000298e948 EFLAGS: 00010a06
RAX: 1ffff11011ae5e00 RBX: 0000000080000000 RCX: ffff888000bdc900
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffff888000bdc900 R09: 0000000000000003
R10: 0000000000000005 R11: 0000000000000000 R12: ffffc9000298ebd3
R13: 0000000000000000 R14: ffff88808d72f000 R15: ffff888036590158
FS:  000055556855e500(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed1011ae5e00 CR3: 0000000042bac000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	4c 8b 35 2f ea bc 08 	mov    0x8bcea2f(%rip),%r14        # 0x8bcea36
   7:	49 83 c7 38          	add    $0x38,%r15
   b:	4c 89 f8             	mov    %r15,%rax
   e:	48 c1 e8 03          	shr    $0x3,%rax
  12:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1)
  16:	74 08                	je     0x20
  18:	4c 89 ff             	mov    %r15,%rdi
  1b:	e8 ce 38 75 f8       	call   0xf87538ee
  20:	4d 03 37             	add    (%r15),%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 f7             	mov    %r14,%rdi
  33:	e8 b6 38 75 f8       	call   0xf87538ee
  38:	4d 8b 36             	mov    (%r14),%r14
  3b:	e8 9e 72 96 01       	call   0x19672de