CVE-2014-4655

Published: 3 July 2014

The snd_ctl_elem_add function in sound/core/control.c in the ALSA control implementation in the Linux kernel before 3.15.2 does not properly maintain the user_ctl_count value, which allows local users to cause a denial of service (integer overflow and limit bypass) by leveraging /dev/snd/controlCX access for a large number of SNDRV_CTL_IOCTL_ELEM_REPLACE ioctl calls.

From the Ubuntu Security Team

A flaw discovered in how the snd_ctl_elem function of the Advanced Linux Sound Architecture (ALSA) handled a reference count. A local user could exploit this flaw to cause a denial of service (integer overflow and limit bypass).

Notes

android kernels (goldfish, grouper, maguro, mako and manta) are not
supported on the Ubuntu Touch 13.10 preview kernels
android kernels (flo, goldfish, grouper, maguro, mako and manta) are
not supported on the Ubuntu Touch 14.04 preview kernels
linux-lts-saucy no longer receives official support
linux-lts-quantal no longer receives official support

Status

References

• https://github.com/torvalds/linux/commit/82262a46627bebb0febcc26664746c25cef08563
• https://bugzilla.redhat.com/show_bug.cgi?id=1113445
• http://www.openwall.com/lists/oss-security/2014/06/26/6
• http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.15.2
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=82262a46627bebb0febcc26664746c25cef08563
• https://ubuntu.com/security/notices/USN-2332-1
• https://ubuntu.com/security/notices/USN-2333-1
• https://ubuntu.com/security/notices/USN-2334-1
• https://ubuntu.com/security/notices/USN-2335-1
• https://ubuntu.com/security/notices/USN-2336-1
• https://ubuntu.com/security/notices/USN-2337-1
• https://www.cve.org/CVERecord?id=CVE-2014-4655
• NVD
• Launchpad
• Debian

Bugs

• https://launchpad.net/bugs/1339304