CVE-2016-9913

Memory leak in the v9fs_device_unrealize_common function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local privileged guest OS users to cause a denial of service (host memory consumption and possibly QEMU process crash) via vectors involving the order of resource cleanup.

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.qemu.org/?p=qemu.git%3Ba=commit%3Bh=4774718e5c194026ba5ee7a28d9be49be3080e42
• http://www.openwall.com/lists/oss-security/2016/12/06/11
• http://www.openwall.com/lists/oss-security/2016/12/08/7
• http://www.securityfocus.com/bid/94729
• https://lists.gnu.org/archive/html/qemu-devel/2016-11/msg03278.html
• https://security.gentoo.org/glsa/201701-49