Stack-based buffer overflow in the parse_tag_11_packet function in fs/ecryptfs/keystore.c in the eCryptfs subsystem in the Linux kernel before 2.6.30.4 allows local users to cause a denial of service (system crash) or possibly gain privileges via vectors involving a crafted eCryptfs file, related to not ensuring that the key signature length in a Tag 11 packet is compatible with the key signature buffer size.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.