Bug 1399528 (CVE-2016-9644) - CVE-2016-9644 kernel: Incorrect fix for CVE-2016-9178
Summary: CVE-2016-9644 kernel: Incorrect fix for CVE-2016-9178
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2016-9644
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1415125
Blocks:
TreeView+ depends on / blocked
 
Reported: 2016-11-29 09:16 UTC by Andrej Nemec
Modified: 2019-09-29 14:00 UTC (History)
35 users (show)

Fixed In Version:
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Environment:
Last Closed: 2016-11-29 09:17:27 UTC
Embargoed:

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Description Andrej Nemec 2016-11-29 09:16:01 UTC 
The __get_user_asm_ex macro in arch/x86/include/asm/uaccess.h in the Linux
kernel 4.4.22 through 4.4.28 contains extended asm statements that are
incompatible with the exception table, which allows local users to obtain root
access on non-SMEP platforms via a crafted application.  NOTE: this
vulnerability exists because of incorrect backporting of the CVE-2016-9178 patch
to older kernels.

Above refers to a new issue which affected some Linux stable lines, which backported 1c109fabbd51863475cd12ac206bdd249aee35af without also backporting 548acf19234dbda5a52d5a8e7e205af46e9da840.

References:

http://seclists.org/oss-sec/2016/q4/535
https://lwn.net/Articles/705264/

Upstream patches:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1c109fabbd51863475cd12ac206bdd249aee35af
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=548acf19234dbda5a52d5a8e7e205af46e9da840
Comment 2 Vladis Dronov 2017-01-20 10:51:47 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1415125]
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