CVE-2017-1000112

CVE Details

Release Date:	2017-08-10
Impact:	Important	What is this?

Description

Linux kernel: Exploitable memory corruption due to UFO to non-UFO pathswitch. 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]:

See more information about CVE-2017-1000112 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v2 metrics

Base Score:	6.9
Vector String:	AV:L/AC:M/Au:N/C:C/I:C/A:C
Version:	2.0
Attack Vector:	Local
Attack Complexity:	Medium
Authentication:	None
Confidentiality Impact:	Complete
Integrity Impact:	Complete
Availability Impact:	Complete

Errata information

Platform	Errata	Release Date
Oracle Linux version 6 (kernel)	ELSA-2017-3200	2017-11-15
Oracle Linux version 6 (kernel-uek)	ELSA-2017-3631	2017-10-24
Oracle Linux version 7 (kernel)	ELSA-2017-2930	2017-10-19
Oracle Linux version 7 (kernel)	ELSA-2017-2930-1	2017-10-20
Oracle Linux version 7 (kernel-uek)	ELSA-2017-3631	2017-10-24
Oracle VM version 3.4 (kernel-uek)	OVMSA-2017-0163	2017-10-26