Bug 1271134 (CVE-2015-7799)

Summary:	CVE-2015-7799 kernel: net: slip: crash when using PPP character device driver
Product:	[Other] Security Response	Reporter:	Martin Prpič <mprpic>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	agordeev, aquini, arm-mgr, bhu, carnil, dhoward, esammons, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, joelsmith, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, kstutsma, lgoncalv, lwang, madhu.chinakonda, matt, mchehab, mcressma, mguzik, nmurray, pholasek, plougher, rt-maint, rvrbovsk, slong, vdronov, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A flaw was discovered in the Linux kernel where issuing certain ioctl() -s commands to the "/dev/ppp" device file could lead to a NULL pointer dereference. A privileged user could use this flaw to cause a kernel crash and denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-11-30 16:22:04 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:	1271135
Bug Blocks:	1271136

Description Martin Prpič 2015-10-13 08:43:34 UTC

The following flaw was found in the Linux kernel:

In the process of using the PPP device driver, if the unit of the PPP device file has been created. On the basis of the above, the ioctl function is used to pass the PPPIOCSMAXCID command and the 0x67084000  parameter (parameters must be satisfied: arg>>16 > 255 and 0xFFFF&arg > 255), which will lead to the use of null pointers in the kernel.

References:

https://code.google.com/p/android/issues/detail?id=187973
http://seclists.org/oss-sec/2015/q4/53
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/net/slip/slhc.c?id=4ab42d78e37a294ac7bc56901d563c642e03c4ae

Comment 1 Martin Prpič 2015-10-13 08:44:25 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1271135]

Comment 2 Josh Boyer 2015-10-21 12:47:49 UTC

Ben Hutchings posted a two patch series to fix this issue, however his mailer corrupted the patches according to the netdev maintainer.

https://www.mail-archive.com/netdev@vger.kernel.org/msg82709.html

Comment 3 Josh Boyer 2015-11-03 13:15:55 UTC

https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=0baa57d8dc32db78369d8b5176ef56c5e2e18ab3

https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=4ab42d78e37a294ac7bc56901d563c642e03c4ae

Comment 4 Fedora Update System 2015-11-19 09:55:33 UTC

kernel-4.2.6-300.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 5 Fedora Update System 2015-11-19 12:20:38 UTC

kernel-4.2.6-200.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2015-11-20 23:21:18 UTC

kernel-4.1.13-100.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.

Comment 9 Vladis Dronov 2015-11-30 16:22:04 UTC

Statement:

This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7 and MRG-2.

This has been rated as having Low security impact as privileged access is required to exploit it, and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.