A use after free issue was discovered in driver/firewire in outbound_phy_packet_callback in the Linux Kernel. In this flaw a local attacker with special privilege may cause a use after free problem when queue_event() fails.
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.