CVE-2024-56767 is a vulnerability in the Linux kernel's dmaengine at_xdmac driver where a null pointer dereference can occur in the at_xdmac_prep_dma_memset function. This happens because the at_xdmac_memset_create_desc function may return NULL under certain conditions such as invalid input length or exhausted memory. The issue has been fixed by adding a check to avoid dereferencing a null pointer.