Bug 7179 - kernel: VDSO randomization not very random CVE-2014-9585
Summary: kernel: VDSO randomization not very random CVE-2014-9585
Status: RESOLVED FIXED
Alias: None
Product: OE-Core
Classification: Build System, Metadata & Runtime
Component: kernel (show other bugs)
Version: unspecified
Hardware: x86 Multiple
: Medium normal
Target Milestone: 1.8
Assignee: Bruce Ashfield
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Reported: 2015-01-19 07:53 UTC by Sona Sarmadi
Modified: 2015-02-17 21:09 UTC (History)
2 users (show)

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OS type for building Yocto: ---
Type of Regression: ---
Verified:
Documentation change: No (bug/feature does not impact docs)

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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.