|Date: (C)2010-09-24 (M)2016-03-13|
|CVSS Score: 7.2||Access Vector: LOCAL|
|Exploitability Subscore: 3.9||Access Complexity: LOW|
|Impact Subscore: 10.0||Authentication: NONE|
| ||Confidentiality: COMPLETE|
| ||Integrity: COMPLETE|
| ||Availability: COMPLETE|
The compat_alloc_user_space functions in include/asm/compat.h files in the Linux kernel before 2.6.36-rc4-git2 on 64-bit platforms do not properly allocate the userspace memory required for the 32-bit compatibility layer, which allows local users to gain privileges by leveraging the ability of the compat_mc_getsockopt function (aka the MCAST_MSFILTER getsockopt support) to control a certain length value, related to a "stack pointer underflow" issue, as exploited in the wild in September 2010.