Bug 1163792 (CVE-2014-7822) - CVE-2014-7822 kernel: splice: lack of generic write checks
Summary: CVE-2014-7822 kernel: splice: lack of generic write checks
Status: CLOSED ERRATA
Alias: CVE-2014-7822
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: impact=moderate,public=20150128,repor...
Keywords: Security
Depends On: 1155900 1155907 1155908 1163798 1163799 1163800
Blocks: 1163802
TreeView+ depends on / blocked
 
Reported: 2014-11-13 13:42 UTC by Petr Matousek
Modified: 2019-06-11 11:13 UTC (History)
21 users (show)

(edit)
A flaw was found in the way the Linux kernel's splice() system call validated its parameters. On certain file systems, a local, unprivileged user could use this flaw to write past the maximum file size, and thus crash the system.
Clone Of:
(edit)
Last Closed: 2019-06-08 02:36:06 UTC


Attachments (Terms of Use)


External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2015:0102 normal SHIPPED_LIVE Important: kernel security and bug fix update 2015-01-29 00:02:51 UTC
Red Hat Product Errata RHSA-2015:0164 normal SHIPPED_LIVE Moderate: kernel security and bug fix update 2015-02-11 02:51:28 UTC
Red Hat Product Errata RHSA-2015:0674 normal SHIPPED_LIVE Important: kernel security and bug fix update 2015-03-11 19:27:24 UTC
Red Hat Product Errata RHSA-2015:0694 normal SHIPPED_LIVE Important: kernel-rt security, bug fix, and enhancement update 2015-03-17 18:39:44 UTC

Description Petr Matousek 2014-11-13 13:42:22 UTC
It was found that there are no size checks in the splice IO path, so it's
possible to send a write past s_maxbytes to a filesystem.  For ext4, at
least, this ends badly, with a BUG_ON.

A local unprivileged user could use this flaw to crash the system.

Acknowledgements:

Red Hat would like to thank Akira Fujita of NEC for reporting this issue.

Upstream patches:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8d0207652cbe27d1f962050737848e5ad4671958

(this patch rearranges splice with a side effect of invoking
generic_write_checks() along the way)

Comment 3 Petr Matousek 2014-11-13 13:49:34 UTC
Statement:

This issue does affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2. Future kernel updates for the respective releases may address this flaw.

Comment 5 errata-xmlrpc 2015-01-28 19:11:03 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2015:0102 https://rhn.redhat.com/errata/RHSA-2015-0102.html

Comment 6 errata-xmlrpc 2015-02-10 21:52:02 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5

Via RHSA-2015:0164 https://rhn.redhat.com/errata/RHSA-2015-0164.html

Comment 11 errata-xmlrpc 2015-03-11 15:28:09 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2015:0674 https://rhn.redhat.com/errata/RHSA-2015-0674.html

Comment 12 errata-xmlrpc 2015-03-17 14:41:03 UTC
This issue has been addressed in the following products:

  MRG for RHEL-6 v.2

Via RHSA-2015:0694 https://rhn.redhat.com/errata/RHSA-2015-0694.html


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