From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> From: Lee Gibson <leegib@xxxxxxxxx> commit 8687bf9ef9551bcf93897e33364d121667b1aadf upstream. Function _rtl92e_wx_set_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. Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Lee Gibson <leegib@xxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210226145157.424065-1-leegib@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/rtl8192e/rtl8192e/rtl_wx.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/staging/rtl8192e/rtl8192e/rtl_wx.c +++ b/drivers/staging/rtl8192e/rtl8192e/rtl_wx.c @@ -419,9 +419,10 @@ static int _rtl92e_wx_set_scan(struct ne struct iw_scan_req *req = (struct iw_scan_req *)b; if (req->essid_len) { - ieee->current_network.ssid_len = req->essid_len; - memcpy(ieee->current_network.ssid, req->essid, - req->essid_len); + int len = min_t(int, req->essid_len, IW_ESSID_MAX_SIZE); + + ieee->current_network.ssid_len = len; + memcpy(ieee->current_network.ssid, req->essid, len); } }
