REDHAT-BUG-2493411: Medium severity Libarchive libarchive vulnerability

A double-free vulnerability exists in the libarchive RAR5 reader subsystem within archivereadsupportformatrar5.c where the state tracking pointer rar->cstate.filteredbuf can be linked to a temporary filter output block during archive decompression. When the unpacking engine subsequently processes an adjacent file or resets its internal state layout via initunpack(), it releases the allocation mapped to filteredbuf but fails to clear or nullify the underlying pointer variable. A specially crafted RAR5 archive can exploit this lingering dangling pointer by forcing a secondary release operation on the exact same memory address, triggering a standard memory-manager abort that immediately crashes the application and results in a Denial of Service (DoS).