wl1251: Fix possible buffer overflow in wl1251_cmd_scan

Function wl1251_cmd_scan calls memcpy without checking the length.
Harden by checking the length is within the maximum allowed size.

Signed-off-by: Lee Gibson <leegib@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210428115508.25624-1-leegib@gmail.com

diff --git a/drivers/net/wireless/ti/wl1251/cmd.c b/drivers/net/wireless/ti/wl1251/cmd.c
index 498c8db..d7a8691 100644 (file)
--- a/drivers/net/wireless/ti/wl1251/cmd.c
+++ b/drivers/net/wireless/ti/wl1251/cmd.c
@@ -454,9 +454,12 @@ int wl1251_cmd_scan(struct wl1251 *wl, u8 *ssid, size_t ssid_len,
                cmd->channels[i].channel = channels[i]->hw_value;
        }
 
-       cmd->params.ssid_len = ssid_len;
-       if (ssid)
-               memcpy(cmd->params.ssid, ssid, ssid_len);
+       if (ssid) {
+               int len = clamp_val(ssid_len, 0, IEEE80211_MAX_SSID_LEN);
+
+               cmd->params.ssid_len = len;
+               memcpy(cmd->params.ssid, ssid, len);
+       }
 
        ret = wl1251_cmd_send(wl, CMD_SCAN, cmd, sizeof(*cmd));
        if (ret < 0) {