CVE-2014-9419

Published: 25 December 2014

The __switch_to function in arch/x86/kernel/process_64.c in the Linux kernel through 3.18.1 does not ensure that Thread Local Storage (TLS) descriptors are loaded before proceeding with other steps, which makes it easier for local users to bypass the ASLR protection mechanism via a crafted application that reads a TLS base address.

From the Ubuntu security team

A flaw was discovered in how Thread Local Storage (TLS) is handled by the task switching function in the Linux kernel for x86_64 based machines. A local user could exploit this flaw to bypass the Address Space Layout Radomization (ASLR) protection mechanism.

Notes

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://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-9419
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/x86?id=f647d7c155f069c1a068030255c300663516420e (v3.19-rc1)
• https://github.com/torvalds/linux/commit/f647d7c155f069c1a068030255c300663516420e
• https://bugzilla.redhat.com/show_bug.cgi?id=1177260
• http://www.openwall.com/lists/oss-security/2014/12/25/1
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f647d7c155f069c1a068030255c300663516420e
• https://ubuntu.com/security/notices/USN-2515-1
• https://ubuntu.com/security/notices/USN-2516-1
• https://ubuntu.com/security/notices/USN-2517-1
• https://ubuntu.com/security/notices/USN-2518-1
• https://ubuntu.com/security/notices/USN-2541-1
• https://ubuntu.com/security/notices/USN-2542-1
• NVD
• Launchpad
• Debian

Bugs

• https://launchpad.net/bugs/1407945