random: entropy: Fix invalid memory access

In sys_rand_get() if the entropy hardware unlikely return error, the
fallgback is using the system timer to and fill the given buffer with
that data.

The problem what that k_cycle_get_32() returns a four bytes integer and
depending the sizeof of the buffer we need copy the right amount of
data. That was not being done properly leading to invalid read/write
memory access.

Fixes #26435

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
1 file changed