USB: chaoskey read offset bug

commit 1d5c47f555c5ae050fad22e4a99f88856cae5d05 upstream.

Rng reads in chaoskey driver could return the same data under
the certain conditions.

Signed-off-by: Alexander Inyukhin <shurick@sectorb.msk.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index 3ad5d19e4d04ede93fb8bc34debdbb9fcf2f4704..23c794813e6a923bff5b0a3719abbea860ee416d 100644 (file)
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -472,7 +472,7 @@ static int chaoskey_rng_read(struct hwrng *rng, void *data,
        if (this_time > max)
                this_time = max;
 
-       memcpy(data, dev->buf, this_time);
+       memcpy(data, dev->buf + dev->used, this_time);
 
        dev->used += this_time;