Bug 1334303 (CVE-2016-4558) - CVE-2016-4558 kernel: bpf: refcnt overflow
Summary: CVE-2016-4558 kernel: bpf: refcnt overflow
Keywords:
Status: CLOSED ERRATA
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:
Depends On: 1334311 1335701
Blocks: 1334304
TreeView+ depends on / blocked
 
Reported: 2016-05-09 11:12 UTC by Andrej Nemec
Modified: 2021-10-21 00:52 UTC (History)
26 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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:
Environment:
Last Closed: 2021-10-21 00:52:32 UTC
Embargoed:

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.
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