From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> From: Lee Gibson <leegib@xxxxxxxxx> 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 <leegib@xxxxxxxxx> Link: https://lore.kernel.org/r/20210301132648.420296-1-leegib@xxxxxxxxx Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/rtl8712/rtl871x_cmd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/staging/rtl8712/rtl871x_cmd.c +++ b/drivers/staging/rtl8712/rtl871x_cmd.c @@ -242,8 +242,10 @@ u8 r8712_sitesurvey_cmd(struct _adapter 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);
