CVE-2016-2549: Input Validation
Function hrtimercancel() waits for the completion from the callback, thus it must not be called inside the callback itself. This was already a problem in the past with ALSA hrtimer driver, and the early commit [fcfdebe70759: ALSA: hrtimer - Fix lock-up] tried to address it.
Upstream patch:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2ba1fe7a06d3624f9a7586d672b55f08f7c670f3
Original report:
http://marc.info/?l=linux-kernel&m=145271261602328
http://marc.info/?l=linux-kernel&m=145288522219596
http://marc.info/?t=145269725600010&r=1&w=2
CVE-ID request and assignment:
http://seclists.org/oss-sec/2016/q1/133
http://seclists.org/oss-sec/2016/q1/410
Other sources
sound/core/hrtimer.c in the Linux kernel before 4.4.1 does not prevent recursive callback access, which allows local users to cause a denial of service (deadlock) via a crafted ioctl call.
— Launchpad
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2016-2549?
The severity of CVE-2016-2549 is low.
How does CVE-2016-2549 impact Linux kernel before version 4.4.1?
CVE-2016-2549 allows local users to cause a denial of service (deadlock) through a crafted ioctl call.
How can I fix CVE-2016-2549 on Ubuntu Linux?
To fix CVE-2016-2549 on Ubuntu, you need to update to Linux kernel version 3.2.0-102.142 or later.
Where can I find more information about CVE-2016-2549?
More information about CVE-2016-2549 can be found in the references: [link](http://www.openwall.com/lists/oss-security/2016/01/19/1), [link](http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2ba1fe7a06d3624f9a7586d672b55f08f7c670f3), [link](http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.1).
What is the affected software for CVE-2016-2549?
The affected software for CVE-2016-2549 includes Ubuntu Linux with kernel versions 3.2.0-102.142 to 4.4.1.