Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
CPU: 1 UID: 0 PID: 5978 Comm: syz.0.17 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:nf_flow_offload_ipv6_forward net/netfilter/nf_flow_table_ip.c:1027 [inline]
RIP: 0010:nf_flow_offload_ipv6_hook+0x2f3/0x32a0 net/netfilter/nf_flow_table_ip.c:1106
Code: 85 c6 03 00 00 e8 6d f0 31 f8 41 bc 14 00 00 00 e9 af 02 00 00 48 8d 4b 60 48 89 4c 24 18 48 c1 e9 03 48 89 8c 24 90 00 00 00 <42> 0f b6 04 21 84 c0 0f 85 de 23 00 00 44 0f b7 73 60 41 83 e6 03
RSP: 0018:ffffc900031d6fe0 EFLAGS: 00010206
RAX: ffffffff898e1101 RBX: 0000000000000002 RCX: 000000000000000c
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc900031d73e0 R08: ffffffff8f7d1e77 R09: 1ffffffff1efa3ce
R10: dffffc0000000000 R11: fffffbfff1efa3cf R12: dffffc0000000000
R13: 1ffff9200063ae1c R14: ffff88816cfc5680 R15: ffffc900031d72e0
FS:  00007fd7653a06c0(0000) GS:ffff8882a9f2e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010000 CR3: 000000011342a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline]
 nf_ingress net/core/dev.c:5900 [inline]
 __netif_receive_skb_core+0x241c/0x2f90 net/core/dev.c:5996
 __netif_receive_skb_one_core net/core/dev.c:6135 [inline]
 __netif_receive_skb+0x72/0x380 net/core/dev.c:6250
 netif_receive_skb_internal net/core/dev.c:6336 [inline]
 netif_receive_skb+0x1cb/0x790 net/core/dev.c:6395
 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: 0033:0x7fd76458f7c9
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:00007fd7653a0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fd7647e6090 RCX: 00007fd76458f7c9
RDX: 000000000000fdef RSI: 0000200000000380 RDI: 0000000000000003
RBP: 00007fd7645f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd7647e6128 R14: 00007fd7647e6090 R15: 00007ffde1f0b2b8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nf_flow_offload_ipv6_forward net/netfilter/nf_flow_table_ip.c:1027 [inline]
RIP: 0010:nf_flow_offload_ipv6_hook+0x2f3/0x32a0 net/netfilter/nf_flow_table_ip.c:1106
Code: 85 c6 03 00 00 e8 6d f0 31 f8 41 bc 14 00 00 00 e9 af 02 00 00 48 8d 4b 60 48 89 4c 24 18 48 c1 e9 03 48 89 8c 24 90 00 00 00 <42> 0f b6 04 21 84 c0 0f 85 de 23 00 00 44 0f b7 73 60 41 83 e6 03
RSP: 0018:ffffc900031d6fe0 EFLAGS: 00010206
RAX: ffffffff898e1101 RBX: 0000000000000002 RCX: 000000000000000c
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc900031d73e0 R08: ffffffff8f7d1e77 R09: 1ffffffff1efa3ce
R10: dffffc0000000000 R11: fffffbfff1efa3cf R12: dffffc0000000000
R13: 1ffff9200063ae1c R14: ffff88816cfc5680 R15: ffffc900031d72e0
FS:  00007fd7653a06c0(0000) GS:ffff8882a9f2e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010000 CR3: 000000011342a000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
   0:	85 c6                	test   %eax,%esi
   2:	03 00                	add    (%rax),%eax
   4:	00 e8                	add    %ch,%al
   6:	6d                   	insl   (%dx),%es:(%rdi)
   7:	f0 31 f8             	lock xor %edi,%eax
   a:	41 bc 14 00 00 00    	mov    $0x14,%r12d
  10:	e9 af 02 00 00       	jmp    0x2c4
  15:	48 8d 4b 60          	lea    0x60(%rbx),%rcx
  19:	48 89 4c 24 18       	mov    %rcx,0x18(%rsp)
  1e:	48 c1 e9 03          	shr    $0x3,%rcx
  22:	48 89 8c 24 90 00 00 	mov    %rcx,0x90(%rsp)
  29:	00
* 2a:	42 0f b6 04 21       	movzbl (%rcx,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 de 23 00 00    	jne    0x2415
  37:	44 0f b7 73 60       	movzwl 0x60(%rbx),%r14d
  3c:	41 83 e6 03          	and    $0x3,%r14d