Bug 608706 (CVE-2016-6323)

Summary:	<sys-libs/glibc-2.23-r3: Missing unwind info in __startcontext causes infinite loop in _Unwind_Backtrace
Product:	Gentoo Security	Reporter:	Thomas Deutschmann (RETIRED) <whissi>
Component:	Vulnerabilities	Assignee:	Gentoo Security <security>
Status:	RESOLVED FIXED
Severity:	normal	CC:	toolchain
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://sourceware.org/ml/libc-alpha/2017-02/msg00079.html
See Also:	https://sourceware.org/bugzilla/show_bug.cgi?id=20435
Whiteboard:	A3 [glsa cve glsa blocked]
Package list:		Runtime testing required:	---
Bug Depends on:	622220
Bug Blocks:

Description Thomas Deutschmann (RETIRED) gentoo-dev

2017-02-09 09:13:02 UTC

CVE-2016-6323

The makecontext function in the GNU C Library (aka glibc or libc6) before 2.25 creates execution contexts incompatible with the unwinder on ARM EABI (32-bit) platforms, which might allow context-dependent attackers to cause a denial of service (hang), as demonstrated by applications compiled using gccgo, related to backtrace generation.

Upstream bug:

https://sourceware.org/bugzilla/show_bug.cgi?id=20435

Upstream patch:

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=9e2ff6c9cc54c0b4402b8d49e4abe7000fde7617

Comment 1 Thomas Deutschmann (RETIRED) gentoo-dev

2017-02-09 09:14:45 UTC

@ Maintainer(s): The vulnerability is fixed in >=sys-libs/glibc-2.25. Please bump the package and tell us if you plan to backport the fix.

Comment 2 SpanKY gentoo-dev

2017-02-09 10:36:49 UTC

this fix i had cherry picked into the first 2.24 patchset already

Comment 3 Matthias Maier gentoo-dev

2017-06-11 16:35:33 UTC

The fix already made it into Patchset 5 for glibc 2.23.

Comment 4 Matthias Maier gentoo-dev

2017-06-19 16:30:55 UTC

commit aa57c4a8ee21fa208a21388c1291260c1dd8c389
Author: Matthias Maier <tamiko@gentoo.org>
Date:   Thu Jun 8 11:20:38 2017 -0500

    profiles: Mask all glibc versions older than 2.23

Comment 5 GLSAMaker/CVETool Bot gentoo-dev

2017-06-20 17:55:34 UTC

This issue was resolved and addressed in
 GLSA 201706-19 at https://security.gentoo.org/glsa/201706-19
by GLSA coordinator Thomas Deutschmann (whissi).