(RHSA-2014:1143) Moderate: kernel security and bug fix update

2014-09-03T04:00:00
ID RHSA-2014:1143
Type redhat
Reporter RedHat
Modified 2017-09-08T12:17:51

Description

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

  • An out-of-bounds memory access flaw was found in the Linux kernel's system call auditing implementation. On a system with existing audit rules defined, a local, unprivileged user could use this flaw to leak kernel memory to user space or, potentially, crash the system. (CVE-2014-3917, Moderate)

This update also fixes the following bugs:

  • A bug in the journaling code (jbd and jbd2) could, under very heavy workload of fsync() operations, trigger a BUG_ON and result in a kernel oops. Also, fdatasync() could fail to immediately write out changes in the file size only. These problems have been resolved by backporting a series of patches that fixed these problems in the respective code on Red Hat Enterprise Linux 6. This update also improves performance of ext3 and ext4 file systems. (BZ#1116027)

  • Due to a bug in the ext4 code, the fdatasync() system call did not force the inode size change to be written to the disk if it was the only metadata change in the file. This could result in the wrong inode size and possible data loss if the system terminated unexpectedly. The code handling inode updates has been fixed and fdatasync() now writes data to the disk as expected in this situation. (BZ#1117665)

  • A workaround to a DMA read problem in the tg3 driver was incorrectly applied to the whole Broadcom 5719 and 5720 chipset family. This workaround is valid only to the A0 revision of the 5719 chips and for other revisions and chips causes occasional Tx timeouts. This update correctly applies the aforementioned workaround only to the A0 revision of the 5719 chips. (BZ#1121017)

  • Due to a bug in the page writeback code, the system could become unresponsive when being under memory pressure and heavy NFS load. This update fixes the code responsible for handling of dirty pages, and dirty page write outs no longer flood the work queue. (BZ#1125246)

All kernel users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.