Permissions, Privileges, and Access Controls in Linux kernel - CVE-2016-9644

Vulnerability details

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

The __get_user_asm_ex macro in arch/x86/include/asm/uaccess.h in the Linux kernel 4.4.22 through 4.4.28 contains extended asm statements that are incompatible with the exception table, which allows local users to obtain root access on non-SMEP platforms via a crafted application. NOTE: this vulnerability exists because of incorrect backporting of the CVE-2016-9178 patch to older kernels.

Affected software

How to mitigate CVE-2016-9644

External References

• http://www.openwall.com/lists/oss-security/2016/11/07/4
• http://www.securityfocus.com/bid/94545
• http://www.ubuntu.com/usn/USN-3146-1
• http://www.ubuntu.com/usn/USN-3146-2
• https://lwn.net/Articles/705220/

Related Security Bulletins

• Permissions, Privileges, and Access Controls in Linux kernel
• Ubuntu update for linux