CVE-2017-1000112: Linux Kernel

High severity, CVSS 7.0. EPSS: 20.8% chance of exploitation in the next 30 days.

Linux kernel: Exploitable memory corruption due to UFO to non-UFO path switch. When building a UFO packet with MSG_MORE __ip_append_data() calls ip_ufo_append_data() to append. However in between two send() calls, the append path can be switched from UFO to non-UFO one, which leads to a memory corruption. In case UFO packet lengths exceeds MTU, copy = maxfraglen - skb->len becomes negative on the non-UFO path and the branch to allocate new skb is taken. This triggers fragmentation and computation of fraggap = skb_prev->len - maxfraglen. Fraggap can exceed MTU, causing copy = datalen - transhdrlen - fraggap to become negative. Subsequently skb_copy_and_csum_bits() writes out-of-bounds. A similar issue is present in IPv6 code. The bug was introduced in e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") on Oct 18 2005.

Affected products

• Linux Linux Kernel: from 2.6.15, before 3.10.108 (fixed in 3.10.108); from 3.11, before 3.16.47 (fixed in 3.16.47); from 3.17, before 3.18.65 (fixed in 3.18.65); from 3.19, before 4.4.82 (fixed in 4.4.82); from 4.5, before 4.9.43 (fixed in 4.9.43); from 4.10, before 4.12.7 (fixed in 4.12.7)

Published 2017-10-05. Last modified 2026-06-17.