RHBA-2011:0338 - Bug Fix Advisory

Topic

An updated strace package that fixes multiple bugs is now available for Red Hat
Enterprise 6.

Description

The strace program intercepts and records the system calls called and received by a running process. It can print a record of each system call, its arguments and its return value.

This update fixes the following bugs:

• Previously, the manual pages and the output of "strace --help" contained inconsistencies. This update corrects these errors. Now, the descriptions for the listed options on the manual pages and in the output of of ‘strace --help’ contain the same information. (BZ#533199)
• Previously, the CLONE_PTRACE flag was set in the arguments of a clone when it was called with the flag CLONE_UNTRACED. Due to this behavior, strace traced the child process for clones called with the flag CLONE_UNTRACED.This update does no no longer trace children with CLONE_UNTRACED. Now, the tracing of child processes behaves as expected. (BZ#642389)
• Previously, the decoding of 64-bit arguments of certain system calls was incorrect. This update corrects this issue. Now, 64-bit arguments of system calls are decoded as expected. (BZ#654515)
• Previously, waitpid waited for children created by clone even when the options "__WCLONE" or "__WALL" were not present. Due to this behavior, the process became suspended. This update does no longer suspend the process in the waitpid system call. (BZ#661748)

All strace users are advised to upgrade to this updated strace package, which fixes these bugs.

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
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 642389 - [6.0] Even if clone() is invoked with CLONE_UNTRACED, the child process can be traced by strace.
• BZ - 654515 - fallocate argument isn't displayed collectly in x86_64
• BZ - 661748 - [6.0] When strace is used, waitpid() without __WCLONE or __WALL option waits for children created by clone().
• BZ - 675106 - Strace sometimes missing vfork()-ed child with -f option

CVEs

(none)

References

(none)