6.9 - RHSA-2013:0522

Problem Description:

Updated gdb packages that fix one security issue and three bugs are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64

3. Description:

The GNU Debugger (GDB) allows debugging of programs written in C, C++, Java, and other languages by executing them in a controlled fashion and then printing out their data.

GDB tried to auto-load certain files (such as GDB scripts, Python scripts, and a thread debugging library) from the current working directory when debugging programs. This could result in the execution of arbitrary code with the user's privileges when GDB was run in a directory that has untrusted content. (CVE-2011-4355)

With this update, GDB no longer auto-loads files from the current directory and only trusts certain system directories by default. The list of trusted directories can be viewed and modified using the "show auto-load safe-path" and "set auto-load safe-path" GDB commands. Refer to the GDB manual, linked to in the References, for further information.

This update also fixes the following bugs:

* When a struct member was at an offset greater than 256 MB, the resulting bit position within the struct overflowed and caused an invalid memory access by GDB. With this update, the code has been modified to ensure that GDB can access such positions. (BZ#795424)

* When a thread list of the core file became corrupted, GDB did not print this list but displayed the "Cannot find new threads: generic error" error message instead. With this update, GDB has been modified and it now prints the thread list of the core file as expected. (BZ#811648)

* GDB did not properly handle debugging of multiple binaries with the same build ID. This update modifies GDB to use symbolic links created for particular binaries so that debugging of binaries that share a build ID now proceeds as expected. Debugging of live programs and core files is now more user-friendly. (BZ#836966)

All users of gdb are advised to upgrade to these updated packages, which contain backported patches to correct these issues.

4. Solution:

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

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/knowledge/articles/11258

5. Bugs fixed (http://bugzilla.redhat.com/):

703238 - CVE-2011-4355 gdb: object file .debug_gdb_scripts section improper input validation 811648 - Cannot find new threads: generic error 836966 - Backport gdb fix to handle identical binaries via additional build-id symlinks