[PATCH] wl1251: Fix possible buffer overflow in wl1251_cmd_scan

[Lee Gibson]

Function wl1251_cmd_scan calls memcpy without checking the length.
A user could control that length and trigger a buffer overflow.
Fix by checking the length is within the maximum allowed size.

Signed-off-by: Lee Gibson <lee...@gmail.com>
---
 drivers/net/wireless/ti/wl1251/cmd.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ti/wl1251/cmd.c 
b/drivers/net/wireless/ti/wl1251/cmd.c
index 498c8db2eb48..e4d028a53d91 100644
--- a/drivers/net/wireless/ti/wl1251/cmd.c
+++ b/drivers/net/wireless/ti/wl1251/cmd.c
@@ -455,8 +455,11 @@ int wl1251_cmd_scan(struct wl1251 *wl, u8 *ssid, size_t 
ssid_len,
        }
 
        cmd->params.ssid_len = ssid_len;
-       if (ssid)
-               memcpy(cmd->params.ssid, ssid, ssid_len);
+       if (ssid) {
+               int len = min_t(int, ssid_len, IEEE80211_MAX_SSID_LEN);
+
+               memcpy(cmd->params.ssid, ssid, len);
+       }
 
        ret = wl1251_cmd_send(wl, CMD_SCAN, cmd, sizeof(*cmd));
        if (ret < 0) {
-- 
2.25.1