RHSA-2015:1120 - Security Advisory

Topic

Updated kernel packages that fix one security issue and one bug are now
available for Red Hat Enterprise Linux 5.9 Advanced Update Support.

Red Hat Product Security has rated this update as having Important security
impact. A Common Vulnerability Scoring System (CVSS) base score, which
gives a detailed severity rating, is available from the CVE link in the
References section.

Description

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

• It was found that the Linux kernel's implementation of vectored pipe read

and write functionality did not take into account the I/O vectors that were
already processed when retrying after a failed atomic access operation,
potentially resulting in memory corruption due to an I/O vector array
overrun. A local, unprivileged user could use this flaw to crash the system
or, potentially, escalate their privileges on the system. (CVE-2015-1805,
Important)

The security impact of this issue was discovered by Red Hat.

This update also fixes the following bug:

• Previously, the signal delivery paths did not clear the TS_USEDFPU flag,

which could confuse the switch_to() function and lead to floating-point
unit (FPU) corruption. With this update, TS_USEDFPU is cleared as expected,
and FPU is no longer under threat of corruption. (BZ#1214239)

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.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server - AUS 5.9 x86_64
• Red Hat Enterprise Linux Server - AUS 5.9 ia64
• Red Hat Enterprise Linux Server - AUS 5.9 i386

Fixes

• BZ - 1202855 - CVE-2015-1805 kernel: pipe: iovec overrun leading to memory corruption

CVEs

• CVE-2015-1805

References

• https://access.redhat.com/security/updates/classification/#important