Bug 1419916 (CVE-2017-2618) - CVE-2017-2618 kernel: Off-by-one error in selinux_setprocattr (/proc/self/attr/fscreate)
Summary: CVE-2017-2618 kernel: Off-by-one error in selinux_setprocattr (/proc/self/att...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2017-2618
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1422368 1422369 1422370 1422371 1422372 1422373 1422717
Blocks: 1419918
TreeView+ depends on / blocked
 
Reported: 2017-02-07 11:59 UTC by Adam Mariš
Modified: 2021-02-17 02:36 UTC (History)
41 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the Linux kernel's handling of clearing SELinux attributes on /proc/pid/attr files. An empty (null) write to this file can crash the system by causing the system to attempt to access unmapped kernel memory.
Clone Of:
Environment:
Last Closed: 2019-06-08 03:07:09 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHEA-2017:3163 0 normal SHIPPED_LIVE new packages: kernel-alt 2017-11-09 14:59:25 UTC
Red Hat Product Errata RHSA-2017:0931 0 normal SHIPPED_LIVE Important: kernel-rt security and bug fix update 2017-04-12 14:51:25 UTC
Red Hat Product Errata RHSA-2017:0932 0 normal SHIPPED_LIVE Important: kernel-rt security and bug fix update 2017-04-12 14:51:03 UTC
Red Hat Product Errata RHSA-2017:0933 0 normal SHIPPED_LIVE Important: kernel security, bug fix, and enhancement update 2017-04-12 17:29:20 UTC

Description Adam Mariš 2017-02-07 11:59:42 UTC 
A flaw was found in the Linux kernels handling of clearing SELinux attributes on /proc/pid/attr files.  An empty (null) write to this file can crash the system by causing the system to attempt to access unmapped kernel memory.

This may lead to local DoS by panicing the system.

Proposed patch:

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=0c461cb727d146c9ef2d3e86214f498b78b7d125

https://marc.info/?l=selinux&m=148588165923772&w=2
Comment 2 Paul Moore 2017-02-07 12:59:47 UTC 
To be clear, the problem is not with libselinux but the kernel itself (see the proposed patch in the original problem description).
Comment 3 Adam Mariš 2017-02-07 13:08:12 UTC 
(In reply to Paul Moore from comment #2)
> To be clear, the problem is not with libselinux but the kernel itself (see
> the proposed patch in the original problem description).

Ah, sorry, my fault. Fixed!
Comment 6 Wade Mealing 2017-02-15 06:39:47 UTC 
Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6 due to a missing commit ( bb646cdb12e75d82258c2f2e7746d5952d3e321a ) which enabled changed system behavior.

This issue does affect Red Hat Enteprise Linux 7 and MRG-2 kernels. A future Linux kernel updates for the respective releases may address this issue.
Comment 7 Wade Mealing 2017-02-15 06:41:23 UTC 
Acknowledgements:

Name: Paul Moore (Red Hat Engineering)
Comment 12 Wade Mealing 2017-02-16 01:15:32 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1422717]
Comment 13 errata-xmlrpc 2017-04-12 10:53:14 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise MRG 2

Via RHSA-2017:0932 https://access.redhat.com/errata/RHSA-2017:0932
Comment 14 errata-xmlrpc 2017-04-12 10:56:53 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:0931 https://access.redhat.com/errata/RHSA-2017:0931
Comment 15 errata-xmlrpc 2017-04-12 13:35:39 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:0933 https://access.redhat.com/errata/RHSA-2017:0933
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