Memory leak in the megasas_handle_dcmd function in hw/scsi/megasas.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (host memory consumption) via MegaRAID Firmware Interface (MFI) commands with the sglist size set to a value over 2 Gb.
Weakness
The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Qemu |
Qemu |
* |
2.8.1.1 (including) |
| Qemu |
Ubuntu |
trusty |
* |
| Qemu |
Ubuntu |
upstream |
* |
| Qemu |
Ubuntu |
xenial |
* |
| Qemu |
Ubuntu |
yakkety |
* |
| Qemu-kvm |
Ubuntu |
precise |
* |
| Qemu-kvm |
Ubuntu |
precise/esm |
* |
| Qemu-kvm |
Ubuntu |
upstream |
* |
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