From: "Jason A. Donenfeld" <Jason@xxxxxxxxx> commit 0d9488ffbf2faddebc6bac055bfa6c93b94056a3 upstream. By using `char` instead of `unsigned char`, certain platforms will sign extend the byte when `w = rol32(*bytes++, input_rotate)` is called, meaning that bit 7 is overrepresented when mixing. This isn't a real problem (unless the mixer itself is already broken) since it's still invertible, but it's not quite correct either. Fix this by using an explicit unsigned type. Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/char/random.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -547,7 +547,7 @@ static void _mix_pool_bytes(struct entro unsigned long i, tap1, tap2, tap3, tap4, tap5; int input_rotate; int wordmask = r->poolinfo->poolwords - 1; - const char *bytes = in; + const unsigned char *bytes = in; __u32 w; tap1 = r->poolinfo->tap1;
