Comment 3 for bug 1748513

I just hit a similar looking bug/oops why another machine (a laptop this time) also running the -proposed kernel:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000009
IP: [<ffffffffb1413ad5>] csum_and_copy_from_iter+0x55/0x4c0
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: veth xt_CHECKSUM iptable_mangle xt_comment ctr ccm ec_sys bridge stp llc nf_log_ipv6 ip6table_filter ip6t_MASQUERADE nf_nat_masquerade_ipv6 ip6table_nat nf_nat_ipv6 ip6_tables nf_log_ip
 ghash_clmulni_intel snd psmouse ahci soundcore r8169 mei_me cfg80211 rtsx_pci mii input_leds libahci mei media vhost_net vhost macvtap macvlan kvm_intel i2c_hid kvm intel_lpss_acpi intel_lpss irqbypass a
CPU: 1 PID: 9573 Comm: dnsmasq Tainted: P W O 4.4.0-113-generic #136-Ubuntu
Hardware name: System76 Lemur/Lemur, BIOS 5.12 02/17/2017
task: ffff88078a910000 ti: ffff88083699c000 task.ti: ffff88083699c000
RIP: 0010:[<ffffffffb1413ad5>] [<ffffffffb1413ad5>] csum_and_copy_from_iter+0x55/0x4c0
RSP: 0018:ffff88083699fa18 EFLAGS: 00010246
RAX: 00000000b1729fd0 RBX: 000000000000001c RCX: ffff88083699fe98
RDX: ffff88083699fa94 RSI: 000000000000001c RDI: ffff88077a0b8824
RBP: ffff88083699fa80 R08: 0000000000000000 R09: ffff88077a0b8824
R10: ffff88077a0b8824 R11: ffff88077a0b8800 R12: ffff88083699fe98
R13: 0000000000000000 R14: 00ffffffb1ea6920 R15: 0000000000000001
FS: 00007f8de7b35880(0000) GS:ffff88086ec80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000009 CR3: 000000078af40000 CR4: 0000000000360670
Stack:
 ffff88084e001600 ffffffffb172d1d7 ffff880776b48600 ffff88083699faaf
 ffff88083699fa94 00000000000001c0 00000000ffffffff 09348cbfe217bf5c
 000000000000001c ffff880776b48600 0000000000000000 ffff88083699fd30
Call Trace:
 [<ffffffffb172d1d7>] ? __alloc_skb+0x87/0x1f0
 [<ffffffffb1782cb6>] ip_generic_getfrag+0x56/0xe0
 [<ffffffffb17abc0f>] raw_getfrag+0xaf/0x100
 [<ffffffffb178450a>] __ip_append_data.isra.45+0x98a/0xb90
 [<ffffffffb17abb60>] ? raw_recvmsg+0x1c0/0x1c0
 [<ffffffffb17abb60>] ? raw_recvmsg+0x1c0/0x1c0
 [<ffffffffb178478a>] ip_append_data.part.46+0x7a/0xe0
 [<ffffffffb1785474>] ip_append_data+0x34/0x40
 [<ffffffffb17ac8a4>] raw_sendmsg+0x724/0xc00
 [<ffffffffb13a4ea0>] ? aa_sk_perm+0x70/0x210
 [<ffffffffb13a5761>] ? aa_sock_msg_perm+0x61/0x150
 [<ffffffffb17bc91b>] inet_sendmsg+0x6b/0xa0
 [<ffffffffb1723b5e>] sock_sendmsg+0x3e/0x50
 [<ffffffffb1724151>] SYSC_sendto+0x101/0x190
 [<ffffffffb1729fd0>] ? sock_setsockopt+0x180/0x830
 [<ffffffffb1397072>] ? apparmor_socket_setsockopt+0x22/0x30
 [<ffffffffb1724c7e>] SyS_sendto+0xe/0x10
 [<ffffffffb184df9f>] entry_SYSCALL_64_fastpath+0x1c/0x93
Code: f3 48 0f 47 de 48 85 db 0f 84 8b 01 00 00 8b 02 49 89 f9 49 89 cc 4c 8b 71 08 89 45 c4 8b 01 a8 04 0f 85 79 01 00 00 4c 8b 79 18 <4d> 8b 6f 08 4d 29 f5 49 39 dd 4c 0f 47 eb a8 02 0f 85 36 02 00
RIP [<ffffffffb1413ad5>] csum_and_copy_from_iter+0x55/0x4c0
 RSP <ffff88083699fa18>
CR2: 0000000000000009
---[ end trace f6995f3da4973edf ]---

I'm not sure if those 2 are related or not.