The is_gpt_valid function in fs/partitions/efi.c in the Linux kernel before 2.6.39 does not check the size of an Extensible Firmware Interface (EFI) GUID Partition Table (GPT) entry, which allows physically proximate attackers to cause a denial of service (heap-based buffer overflow and OOPS) or obtain sensitive information from kernel heap memory by connecting a crafted GPT storage device, a different vulnerability than CVE-2011-1577.