Bug 1113967 (CVE-2014-4667)

Summary:	CVE-2014-4667 kernel: sctp: sk_ack_backlog wrap-around problem
Product:	[Other] Security Response	Reporter:	Petr Matousek <pmatouse>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	agordeev, anton, aquini, bhu, davej, dhoward, esammons, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, jonathan, jross, jrusnack, jwboyer, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, matt, mchehab, mcressma, npajkovs, pholasek, plougher, rt-maint, rvrbovsk, vkrizan, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	An integer underflow flaw was found in the way the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation processed certain COOKIE_ECHO packets. By sending a specially crafted SCTP packet, a remote attacker could use this flaw to prevent legitimate connections to a particular SCTP server socket to be made.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-09-19 09:33:10 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1085932, 1112726, 1113969, 1113971, 1113972, 1113973
Bug Blocks:	1110682

Description Petr Matousek 2014-06-27 11:10:37 UTC

Description of the problem:
For a TCP-style socket, while processing the COOKIE_ECHO chunk in
sctp_sf_do_5_1D_ce(), after it has passed a series of sanity check, a
new association would be created in sctp_unpack_cookie(), but afterwards,
some processing maybe failed, and sctp_association_free() will be called
to free the previously allocated association, in sctp_association_free(),
sk_ack_backlog value is decremented for this socket, since the initial
value for sk_ack_backlog is 0, after the decrement, it will be 65535, a
wrap-around problem happens, and if we want to establish new associations
afterward in the same socket, ABORT would be triggered since sctp deem the
accept queue as full. 

A remote attacker can block further connection to the particular sctp
server socket by sending a specially crafted sctp packet.

Upstream patch:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d3217b15a19a4779c39b212358a5c71d725822ee

Acknowledgements:

Red Hat would like to thank Gopal Reddy Kodudula of Nokia Siemens Networks for reporting this issue.

Comment 3 Petr Matousek 2014-06-27 11:14:42 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1113973]

Comment 4 Fedora Update System 2014-06-30 10:28:45 UTC

kernel-3.14.9-200.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 5 Petr Matousek 2014-07-22 16:15:27 UTC

Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5.

Comment 6 errata-xmlrpc 2014-07-22 18:04:57 UTC

This issue has been addressed in following products:

  MRG for RHEL-6 v.2

Via RHSA-2014:0913 https://rhn.redhat.com/errata/RHSA-2014-0913.html

Comment 7 Fedora Update System 2014-07-25 10:08:27 UTC

kernel-3.14.13-100.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 8 Martin Prpič 2014-08-05 12:09:18 UTC

IssueDescription:

An integer underflow flaw was found in the way the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation processed certain COOKIE_ECHO packets. By sending a specially crafted SCTP packet, a remote attacker could use this flaw to prevent legitimate connections to a particular SCTP server socket to be made.

Comment 9 errata-xmlrpc 2014-08-06 17:11:57 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 7

Via RHSA-2014:1023 https://rhn.redhat.com/errata/RHSA-2014-1023.html

Comment 10 errata-xmlrpc 2014-09-09 17:57:35 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2014:1167 https://rhn.redhat.com/errata/RHSA-2014-1167.html