Instead of reading the desired 5 bytes of the actual target field,
the code was reading 8. This could result in a corrupted value if the
trailing 3 bytes were non-zero, so instead use an appropriately sized
and zero-initialized bounce buffer, and read only 5 bytes before casting
to u64.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
{
uint64_t n = 0;
uint8_t count = 0;
+ u8 bksv[sizeof(n)] = { };
- memcpy(&n, hdcp->auth.msg.hdcp1.bksv, sizeof(uint64_t));
+ memcpy(bksv, hdcp->auth.msg.hdcp1.bksv, sizeof(hdcp->auth.msg.hdcp1.bksv));
+ n = *(uint64_t *)bksv;
while (n) {
count++;