CVE-2017-2636

Published: 7 March 2017

Race condition in drivers/tty/n_hdlc.c in the Linux kernel through 4.10.1 allows local users to gain privileges or cause a denial of service (double free) by setting the HDLC line discipline.

From the Ubuntu security team

Alexander Popov discovered that the N_HDLC line discipline implementation in the Linux kernel contained a double-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly gain administrative privileges.

Priority

High

CVSS 3 base score: 7.8

Status

Notes

android kernels (flo, goldfish, grouper, maguro, mako and manta) are
not supported on the Ubuntu Touch 14.10 and earlier preview kernels
linux-lts-saucy no longer receives official support
linux-lts-quantal no longer receives official support

all of our kernels are affected as CONFIG_N_HDLC=m is set
in all releases

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-2636
• http://www.openwall.com/lists/oss-security/2017/03/07/6
• https://ubuntu.com/security/notices/USN-3219-1
• https://ubuntu.com/security/notices/USN-3218-1
• https://ubuntu.com/security/notices/USN-3219-2
• https://ubuntu.com/security/notices/USN-3220-1
• https://ubuntu.com/security/notices/USN-3220-2
• https://ubuntu.com/security/notices/USN-3221-1
• https://ubuntu.com/security/notices/USN-3221-2
• https://ubuntu.com/security/notices/USN-3220-3
• NVD
• Launchpad
• Debian

Bugs