From 80f8c5b434f94926c6489d7350d58aecb53ab70f Mon Sep 17 00:00:00 2001 From: Jussi Kivilinna Date: Thu, 4 Mar 2010 18:27:02 +0200 Subject: [PATCH] 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: Jussi Kivilinna Signed-off-by: John W. Linville --- drivers/net/wireless/rndis_wlan.c | 33 +++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c index 9f6d6bf06b8e..a4f70de99cdd 100644 --- a/drivers/net/wireless/rndis_wlan.c +++ b/drivers/net/wireless/rndis_wlan.c @@ -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) -- 2.20.1