BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 93f46067 P4D 93f46067 PUD 8aae1067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4069 Comm: syz-executor.0 Not tainted 5.1.0+ #12
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8880922ff5d0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888099c824b6 RCX: ffffc9000e8b4000
RDX: 1ffff1101339049b RSI: ffffffff861c9058 RDI: ffff88809638fa40
RBP: ffff8880922ff600 R08: ffff8880642183c0 R09: ffffed1015d06be0
R10: ffffed1015d06bdf R11: ffff8880ae835efb R12: ffff88809638fa40
R13: 0000000000000001 R14: ffff88809638fa98 R15: 0000000000000000
FS:  00007fe712d84700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000006820d000 CR4: 00000000001406f0
Call Trace:
 dst_input include/net/dst.h:439 [inline]
 ip6_rcv_finish+0x1e7/0x320 net/ipv6/ip6_input.c:80
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:276
 __netif_receive_skb_one_core+0x12a/0x1f0 net/core/dev.c:4990
 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5104
 netif_receive_skb_internal+0x117/0x5c0 net/core/dev.c:5207
 napi_frags_finish net/core/dev.c:5774 [inline]
 napi_gro_frags+0xade/0xd10 net/core/dev.c:5848
 tun_get_user+0x2f3f/0x3ff0 drivers/net/tun.c:1991
 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2037
 call_write_iter include/linux/fs.h:1872 [inline]
 do_iter_readv_writev+0x5fd/0x900 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:951
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1015
 do_writev+0x15b/0x330 fs/read_write.c:1058
 __do_sys_writev fs/read_write.c:1131 [inline]
 __se_sys_writev fs/read_write.c:1128 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1128
 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c61
Code: 75 14 b8 14 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 e4 b9 fb ff c3 48 83 ec 08 e8 1a 2d 00 00 48 89 04 24 b8 14 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 63 2d 00 00 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fe712d83ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000066 RCX: 0000000000458c61
RDX: 0000000000000001 RSI: 00007fe712d83c00 RDI: 00000000000000f0
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 00007fe712d849d0 R11: 0000000000000293 R12: 00007fe712d846d4
R13: 00000000004c77d2 R14: 00000000004dd9d0 R15: 00000000ffffffff
Modules linked in:
CR2: 0000000000000000
---[ end trace 70d2855f5a2cf79c ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8880922ff5d0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888099c824b6 RCX: ffffc9000e8b4000
RDX: 1ffff1101339049b RSI: ffffffff861c9058 RDI: ffff88809638fa40
RBP: ffff8880922ff600 R08: ffff8880642183c0 R09: ffffed1015d06be0
R10: ffffed1015d06bdf R11: ffff8880ae835efb R12: ffff88809638fa40
R13: 0000000000000001 R14: ffff88809638fa98 R15: 0000000000000000
FS:  00007fe712d84700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000006820d000 CR4: 00000000001406f0