Bug 1302219 (CVE-2016-2070)

Summary:	CVE-2016-2070 kernel: potential division by zero in TCP code
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	agordeev, aquini, dhoward, fhrbata, joelsmith, kernel-mgr, kstutsma, lwang, mguzik, nmurray, pholasek, plougher, rvrbovsk, slawomir, slong, vdronov
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A divide-by-zero vulnerability was found in a way the kernel processes TCP connections. The error can occur if a connection starts another cwnd reduction phase by setting tp->prior_cwnd to the current cwnd (0) in tcp_init_cwnd_reduction(). A remote, unauthenticated attacker could use this flaw to crash the kernel (denial of service).	Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-01-28 11:27:28 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1302673
Bug Blocks:	1302222

Description Andrej Nemec 2016-01-27 08:55:24 UTC

A divide-by-zero vulnerability was found in a way the kernel processes TCP connections. The error can occur if a connection starts another cwnd reduction phase by setting tp->prior_cwnd to the current cwnd (0) in tcp_init_cwnd_reduction(). A remote, unauthenticated attacker could use this flaw to crash the kernel (denial of service).

Original bug report:

https://lkml.org/lkml/2015/12/21/435

Oss-security reference:

http://seclists.org/oss-sec/2016/q1/198

CVE assignment:

http://seclists.org/oss-sec/2016/q1/211

Upstream fix:

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8b8a321ff72c785ed5e8b4cf6eda20b35d427390

Comment 2 Vladis Dronov 2016-01-28 11:23:04 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1302673]

Comment 3 Vladis Dronov 2016-01-28 11:27:04 UTC

Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7 and MRG-2 as the code with the flaw is not present in the products listed.