From: Lee Gibson Date: Mon, 1 Mar 2021 13:26:48 +0000 (+0000) Subject: staging: rtl8712: Fix possible buffer overflow in r8712_sitesurvey_cmd X-Git-Tag: v4.4.262~28 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e6cd3f4569d47af6a80b7a1b4ce96128362efcd3;p=thirdparty%2Fkernel%2Fstable.git staging: rtl8712: Fix possible buffer overflow in r8712_sitesurvey_cmd commit b93c1e3981af19527beee1c10a2bef67a228c48c upstream. Function r8712_sitesurvey_cmd 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 Link: https://lore.kernel.org/r/20210301132648.420296-1-leegib@gmail.com Cc: stable Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/rtl8712/rtl871x_cmd.c b/drivers/staging/rtl8712/rtl871x_cmd.c index 562a102031277..b4eb6af4e5656 100644 --- a/drivers/staging/rtl8712/rtl871x_cmd.c +++ b/drivers/staging/rtl8712/rtl871x_cmd.c @@ -242,8 +242,10 @@ u8 r8712_sitesurvey_cmd(struct _adapter *padapter, psurveyPara->ss_ssidlen = 0; memset(psurveyPara->ss_ssid, 0, IW_ESSID_MAX_SIZE + 1); if ((pssid != NULL) && (pssid->SsidLength)) { - memcpy(psurveyPara->ss_ssid, pssid->Ssid, pssid->SsidLength); - psurveyPara->ss_ssidlen = cpu_to_le32(pssid->SsidLength); + int len = min_t(int, pssid->SsidLength, IW_ESSID_MAX_SIZE); + + memcpy(psurveyPara->ss_ssid, pssid->Ssid, len); + psurveyPara->ss_ssidlen = cpu_to_le32(len); } set_fwstate(pmlmepriv, _FW_UNDER_SURVEY); r8712_enqueue_cmd(pcmdpriv, ph2c);