CCM Tag Length Stack Buffer Overflow in MbedTLS

FSP versions prior to v6.3.0 contain a stack buffer overflow vulnerability in the CCM alt process (rm_psa_crypto/ccm_alt_process.c). In the CCM decrypt path, the sce_ccm_crypt_and_tag function copies tag_len bytes from a caller-supplied tag into a 16-byte local buffer mac_buff with no bounds checking. When tag_len > 16, this causes stack buffer overflow of the 16-byte mac_buff buffer, potential local memory corruption leading to arbitrary code execution or device crash, and stack corruption that may enable more severe exploits depending on context.