(RHSA-2017:2869) Important: kernel security and bug fix update

2017-10-10T16:15:50
ID RHSA-2017:2869
Type redhat
Reporter RedHat
Modified 2017-10-10T16:25:18

Description

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

  • A race condition was found in the Linux kernel, present since v3.14-rc1 through v4.12. The race happens between threads of inotify_handle_event() and vfs_rename() while running the rename operation against the same file. As a result of the race the next slab data or the slab's free list pointer can be corrupted with attacker-controlled data, which may lead to the privilege escalation. (CVE-2017-7533, Important)

Red Hat would like to thank Leilei Lin (Alibaba Group), Fan Wu (The University of Hong Kong), and Shixiong Zhao (The University of Hong Kong) for reporting this issue.

Bug Fix(es):

  • Previously, the 'stack:TID' annotation was applied to correctly mark the thread stack in a /proc/<pid>/maps file and it required processing the entire thread list to find the task of a stack Virtual Memory Area (VMA). Consequently, rendering and accessing /proc/<pid>/maps took a long time on systems with a large number of threads running. This update removes the annotation to make the /proc/<pid>/maps and /proc/<pid>/numa_maps files usable for higher thread counts. As a result, the system performance while rendering and accessing /proc/<pid>/maps has improved significantly. (BZ#1481722)