There are two mutex locking issues that Roland Dowdeswell noticed in the memory ccache. The first one is in cc_memory.c:krb5_mcc_initialize(). When it is free(3)ing the existing credentials it does not lock the data structures and hence two separate threads can run into issues. The same problem exists in cc_memory.c:krb5_mcc_destroy(). Commit By: jaltman Revision: 20555 Changed Files: U trunk/src/lib/krb5/ccache/cc_memory.c