The clip_mkip function in net/atm/clip.c of the ATM subsystem in Linux kernel allows remote attackers to cause a denial of service (panic) via unknown vectors that cause the ATM subsystem to access the memory of socket buffers after they are freed (freed pointer dereference).
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.