staging: r8188eu: prevent ->Ssid overflow in rtw_wx_set_scan()

This code has a check to prevent read overflow but it needs another
check to prevent writing beyond the end of the ->Ssid[] array.

Fixes: 2b42bd58b321 ("staging: r8188eu: introduce new os_dep dir for RTL8188eu driver")
Cc: stable <[email protected]>
Signed-off-by: Denis Efremov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
index a802c1e7b456dab8406a9126a5acdf0e8016eb06..9c1f576e067ae2216092a06b80917a77be6d55c7 100644 (file)
--- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c
+++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
@@ -1131,9 +1131,11 @@ static int rtw_wx_set_scan(struct net_device *dev, struct iw_request_info *a,
                                                break;
                                        }
                                        sec_len = *(pos++); len -= 1;
-                                       if (sec_len > 0 && sec_len <= len) {
+                                       if (sec_len > 0 &&
+                                           sec_len <= len &&
+                                           sec_len <= 32) {
                                                ssid[ssid_index].SsidLength = sec_len;
-                                               memcpy(ssid[ssid_index].Ssid, pos, ssid[ssid_index].SsidLength);
+                                               memcpy(ssid[ssid_index].Ssid, pos, sec_len);
                                                ssid_index++;
                                        }
                                        pos += sec_len;