soc/amd/common/psp_smi_flash: add buffer overflow checks

Before 'handle_psp_command' calls any of the functions in this file, it
make sure that the 'size' field in the command buffer's header doesn't
indicate that the command buffer is larger than the SMM memory region
reserved for it.

The read/write command buffer has a 'num_bytes' field to indicate how
many bytes should be read from the SPI flash and put into the data
buffer within the command buffer or how many bytes from this buffer
should be written to the flash. While we should be able to assume that
the PSP won't send us malformed command buffer, we should still better
check this just to be sure.

Test=When selecting SOC_AMD_COMMON_BLOCK_PSP_SMI, Mandolin still builds

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ib4e8514eedc3ad154a705c8a1e85d367e452dbed
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83778
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions