Bug 7179

Summary:	kernel: VDSO randomization not very random CVE-2014-9585
Product:	[Build System, Metadata & Runtime] OE-Core	Reporter:	Sona Sarmadi <sona.sarmadi>
Component:	kernel	Assignee:	Bruce Ashfield <bruce.ashfield>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	Medium	CC:	bruce.ashfield, tom.zanussi
Version:	unspecified
Target Milestone:	1.8
Hardware:	x86
OS:	Multiple
Whiteboard:
OS type for building Yocto:	---	Type of Regression:	---
Verified:		Documentation change:	No (bug/feature does not impact docs)

Description Sona Sarmadi 2015-01-19 07:53:12 UTC

The vdso_addr function in arch/x86/vdso/vma.c in the Linux kernel through 3.18.2 does not properly choose memory locations for the vDSO area, which makes it easier for local users to bypass the ASLR protection mechanism by guessing a location at the end of a PMD.

The fix can be found here:
https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/commit/?h=x86/vdso&id=bc3b94c31d65e761ddfe150d02932c65971b74e2
http://marc.info/?l=linux-kernel&m=141909723019695&w=2

References:
https://bugzilla.kernel.org/show_bug.cgi?id=89591
https://security-tracker.debian.org/tracker/CVE-2014-9585

Comment 1 Bruce Ashfield 2015-01-22 15:48:01 UTC

I have -stable updates for 3.10, 3.14 and 3.17 that will address this. And then we'll
remove 3.17, to make it a non-issue for the newest kernels.