Commit 80f8c5b4 authored by Jussi Kivilinna's avatar Jussi Kivilinna Committed by John W. Linville

rndis_wlan: copy only useful data from rndis_command respond

rndis_query_oid() uses full output buffer size to copy response buffer
from rndis_command()/device. This doesn't cause problems as response buffer
is sized based on output buffer but does copy extra unset bytes.
So change rndis_query_oid() so that only meaningful bytes are being copied.

Also in case of malfunctioning device/cable/etc returned data offset from
device might be wrong so bound check memory access correctly, so add
checks for this.

v2: fixed to use new netdev_dbg/warn/etc instead of old devdbg/warn/etc
Signed-off-by: default avatarJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent eae44756
......@@ -704,6 +704,7 @@ static int rndis_query_oid(struct usbnet *dev, __le32 oid, void *data, int *len)
struct rndis_query_c *get_c;
} u;
int ret, buflen;
int resplen, respoffs, copylen;
buflen = *len + sizeof(*u.get);
if (buflen < CONTROL_BUFFER_SIZE)
......@@ -733,11 +734,34 @@ static int rndis_query_oid(struct usbnet *dev, __le32 oid, void *data, int *len)
le32_to_cpu(u.get_c->status));
if (ret == 0) {
memcpy(data, u.buf + le32_to_cpu(u.get_c->offset) + 8, *len);
resplen = le32_to_cpu(u.get_c->len);
respoffs = le32_to_cpu(u.get_c->offset) + 8;
ret = le32_to_cpu(u.get_c->len);
if (ret > *len)
*len = ret;
if (respoffs > buflen) {
/* Device returned data offset outside buffer, error. */
netdev_dbg(dev->net, "%s(%s): received invalid "
"data offset: %d > %d\n", __func__,
oid_to_string(oid), respoffs, buflen);
ret = -EINVAL;
goto exit_unlock;
}
if ((resplen + respoffs) > buflen) {
/* Device would have returned more data if buffer would
* have been big enough. Copy just the bits that we got.
*/
copylen = buflen - respoffs;
} else {
copylen = resplen;
}
if (copylen > *len)
copylen = *len;
memcpy(data, u.buf + respoffs, copylen);
*len = resplen;
ret = rndis_error_status(u.get_c->status);
if (ret < 0)
......@@ -746,6 +770,7 @@ static int rndis_query_oid(struct usbnet *dev, __le32 oid, void *data, int *len)
le32_to_cpu(u.get_c->status), ret);
}
exit_unlock:
mutex_unlock(&priv->command_lock);
if (u.buf != priv->command_buffer)
......
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