CVE-2019-11683: "GRO packet of death" issue in the Linux kernel

[Andrey Konovalov <andreyknvl () gmail com>]

Hi,

syzbot has reported a remotely triggerable memory corruption in the
Linux kernel. It's been introduced quite recently in e20cf8d3f1f7
("udp: implement GRO for plain UDP sockets.") and only affects the 5.0
(stable) release (so the name is a bit overhyped :).

CVE-2019-11683 description:

udp_gro_receive_segment in net/ipv4/udp_offload.c in the Linux kernel
5.x through 5.0.11 allows remote attackers to cause a denial of
service (slab-out-of-bounds memory corruption) or possibly have
unspecified other impact via UDP packets with a 0 payload, because of
mishandling of padded packets, aka the "GRO packet of death" issue.

Fix (not yet upstream):

https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=4dd2b82d5adfbe0b1587ccad7a8f76d826120f37

Thanks!