Bug 155234

Summary:	CAN-2005-0137 ia64 syscall_table DoS
Product:	Red Hat Enterprise Linux 3	Reporter:	Mark J. Cox <mjc>
Component:	kernel	Assignee:	Jason Baron <jbaron>
Status:	CLOSED ERRATA	QA Contact:	Brian Brock <bbrock>
Severity:	high	Docs Contact:
Priority:	medium
Version:	3.0	CC:	jparadis, knoel, peterm, petrides, riel, security-response-team
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	ia64
OS:	Linux
Whiteboard:	reported=20050208,embargo=20050311,impact=important,source=vendorsec
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2005-04-22 20:17:40 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:

Description Mark J. Cox 2005-04-18 12:03:41 UTC

Jason Baron noted that this issue also affected RHEL3

+++ This bug was initially created as a clone of Bug #148860 +++

Mike O'Connor mentioned to vendor-sec on Feb08:

        The number of entries in the syscall_table is incorrect. The
        exception handling code assumes that there are 255 entries but
        there are only 254.  If any user issues syscall number
        1024+255 (1279), the exception handler jumps to garbage, and
        voila -- instead of ENOSYS, you get a DoS.

This looks valid, arch/ia64/kernel/entry.S only contains 255 entries
(see end of file) and is missing a "data8 ia64_ni_syscall" from the end.

DoS itself not verified but should be easily reproducable.

** Currently embargoed, no date yet set. **

Comment 1 Mark J. Cox 2005-04-18 12:05:05 UTC

"below is the tested rhel3 version of the patch. 

-Jason"

--- linux-2.4.21/arch/ia64/kernel/entry.S.bak
+++ linux-2.4.21/arch/ia64/kernel/entry.S
@@ -1305,3 +1305,4 @@ sys_call_table:
        data8 ia64_ni_syscall
        data8 ia64_ni_syscall
        data8 ia64_ni_syscall
+       data8 ia64_ni_syscall

Comment 2 Ernie Petrides 2005-04-18 17:28:14 UTC

A fix for this problem was committed to the RHEL3 E5 patch
pool on 13-Apr-2005 (in kernel version 2.4.21-27.0.3.EL).

Comment 3 Ernie Petrides 2005-04-18 17:28:54 UTC

A fix for this problem was also committed to the RHEL3 U5
patch pool on 15-Apr-2005 (in kernel version 2.4.21-32.EL).

Comment 4 Josh Bressers 2005-04-22 20:17:41 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2005-293.html

Comment 5 Tim Powers 2005-05-18 13:29:25 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2005-294.html