CVE-2010-2942

The actions implementation in the network queueing functionality in the Linux kernel before 2.6.36-rc2 does not properly initialize certain structure members when performing dump operations, which allows local users to obtain potentially sensitive information from kernel memory via vectors related to (1) the tcf_gact_dump function in net/sched/act_gact.c, (2) the tcf_mirred_dump function in net/sched/act_mirred.c, (3) the tcf_nat_dump function in net/sched/act_nat.c, (4) the tcf_simp_dump function in net/sched/act_simple.c, and (5) the tcf_skbedit_dump function in net/sched/act_skbedit.c.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• http://git.kernel.org/?p=linux/kernel/git/davem/net-2.6.git%3Ba=commit%3Bh=1c40be12f7d8ca1d387510d39787b12e512a7ce8
• http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00004.html
• http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00005.html
• http://lists.opensuse.org/opensuse-security-announce/2010-11/msg00000.html
• http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00004.html
• http://lists.opensuse.org/opensuse-security-announce/2011-02/msg00000.html
• http://patchwork.ozlabs.org/patch/61857/
• http://secunia.com/advisories/41512
• http://secunia.com/advisories/46397
• http://support.avaya.com/css/P8/documents/100113326
• http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.36-rc2
• http://www.openwall.com/lists/oss-security/2010/08/18/1
• http://www.openwall.com/lists/oss-security/2010/08/19/4
• http://www.redhat.com/support/errata/RHSA-2010-0723.html
• http://www.redhat.com/support/errata/RHSA-2010-0771.html
• http://www.redhat.com/support/errata/RHSA-2010-0779.html
• http://www.securityfocus.com/archive/1/520102/100/0/threaded
• http://www.securityfocus.com/bid/42529
• http://www.ubuntu.com/usn/USN-1000-1
• http://www.vmware.com/security/advisories/VMSA-2011-0012.html
• http://www.vupen.com/english/advisories/2010/2430
• http://www.vupen.com/english/advisories/2011/0298
• https://bugzilla.redhat.com/show_bug.cgi?id=624903