Bug 1334303 (CVE-2016-4558) - CVE-2016-4558 kernel: bpf: refcnt overflow
Summary: CVE-2016-4558 kernel: bpf: refcnt overflow
Status: NEW
Alias: CVE-2016-4558
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard: impact=important,public=20160428,repo...
Keywords: Security
Depends On: 1334311 1335701
Blocks: 1334304
TreeView+ depends on / blocked
 
Reported: 2016-05-09 11:12 UTC by Andrej Nemec
Modified: 2019-06-08 21:11 UTC (History)
29 users (show)

(edit)
A flaw was found in the Linux kernel's implementation of BPF in which systems can application can overflow a 32 bit refcount in both program and map refcount.  This refcount can wrap and end up a user after free.
Clone Of:
(edit)
Last Closed:


Attachments (Terms of Use)

Description Andrej Nemec 2016-05-09 11:12:52 UTC
A flaw was found in the Linux kernels implementation of BPF in which systems with more than 32GB of physical memory and unlimited RLIMIT_MEMLOCK settings an application can overflow a 32 bit refcount.  

Additionally in the same environment, malicious applications can overflow a map refcount on larger memory (1Tb).  When the overflow wraps to zero a reference can be held while being free'd.  This can lead to a use after free 

CVE assignment:

http://seclists.org/oss-sec/2016/q2/266

Upstream fix:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=92117d8443bc5afacc8d5ba82e541946310f106e

Comment 1 Adam Mariš 2016-05-09 11:29:03 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1334311]

Comment 3 Wade Mealing 2016-05-13 02:08:16 UTC
Statement:

This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 4, 5, 6, 7 and Red Hat Enterprise MRG 2.

Comment 6 Fedora Update System 2016-05-14 23:22:20 UTC
kernel-4.5.4-300.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2016-05-25 00:53:04 UTC
kernel-4.4.10-200.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 9 Fedora Update System 2016-06-02 14:59:04 UTC
kernel-4.5.5-201.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.


Note You need to log in before you can comment on or make changes to this bug.