Use-After-Free in ALSA PCM Playback Kernel Module (CVE-2017-8246)

Release Date: 
May 1, 2017
Advisory ID: 
QCIR-2017-00036-1
Summary: 

The following security vulnerabilities have been identified:

 
CVE-2017-8246

In function msm_pcm_playback_close(), prtd is assigned substream->runtime->private_data. Later, prtd is freed. However, prtd is not sanitized and set to NULL, resulting in a dangling pointer. There are other functions that access the same memory (substream->runtime->private_data) with a NULL check, such as msm_pcm_volume_ctl_put(), which means this freed memory could be used.

Access Vector: Local
Security Risk: Medium
Vulnerability: CWE-416 Use After Free

Affected Versions:
All Android releases from CAF using the Linux kernel.

Acknowledgement: 

Qualcomm Innovation Center, Inc. (QuIC) thanks Seven Shen from the Trend Micro Mobile Threat Research Team for bringing this issue to QuIC’s attention. 

Revisions: 

Initial revision

Contact: 
security-advisory@quicinc.com