UBUNTU-CVE-2014-2038

Description

The nfs_can_extend_write function in fs/nfs/write.c in the Linux kernel before 3.13.3 relies on a write delegation to extend a write operation without a certain up-to-date verification, which allows local users to obtain sensitive information from kernel memory in opportunistic circumstances by writing to a file in an NFS filesystem and then reading the same file.

Affected Systems

• ubuntu•linux

  < 3.13.0-10.30 | < 4.2.0-16.19

• ubuntu•linux-aws

  < 4.4.0-1002.2 | < 4.4.0-1001.10

• ubuntu•linux-gke

  < 4.4.0-1003.3

• ubuntu•linux-hwe

  < 4.8.0-36.36~16.04.1

• ubuntu•linux-lts-utopic

  < 3.16.0-25.33~14.04.2

• ubuntu•linux-lts-vivid

  < 3.19.0-18.18~14.04.1

• ubuntu•linux-lts-wily

  < 4.2.0-18.22~14.04.1

• ubuntu•linux-lts-xenial

  < 4.4.0-13.29~14.04.1

• ubuntu•linux-raspi2

  < 4.2.0-1013.19

• ubuntu•linux-snapdragon

  < 4.4.0-1012.12

References (5)

• https://ubuntu.com/security/CVE-2014-2038
• https://git.kernel.org/linus/263b4509ec4d47e0da3e753f85a39ea12d1eff24
• https://ubuntu.com/security/notices/USN-2137-1
• https://ubuntu.com/security/notices/USN-2140-1
• https://www.cve.org/CVERecord?id=CVE-2014-2038