From: Dan Carpenter Date: Fri, 5 Mar 2021 08:56:32 +0000 (+0300) Subject: staging: rtl8188eu: fix potential memory corruption in rtw_check_beacon_data() X-Git-Tag: v4.4.262~29 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=577d460b95d5475de227a273fa099754021cb014;p=thirdparty%2Fkernel%2Fstable.git staging: rtl8188eu: fix potential memory corruption in rtw_check_beacon_data() commit d4ac640322b06095128a5c45ba4a1e80929fe7f3 upstream. The "ie_len" is a value in the 1-255 range that comes from the user. We have to cap it to ensure that it's not too large or it could lead to memory corruption. Fixes: 9a7fe54ddc3a ("staging: r8188eu: Add source files for new driver - part 1") Signed-off-by: Dan Carpenter Cc: stable Link: https://lore.kernel.org/r/YEHyQCrFZKTXyT7J@mwanda Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/rtl8188eu/core/rtw_ap.c b/drivers/staging/rtl8188eu/core/rtw_ap.c index f5cedbbc552af..d14a2313fccea 100644 --- a/drivers/staging/rtl8188eu/core/rtw_ap.c +++ b/drivers/staging/rtl8188eu/core/rtw_ap.c @@ -921,6 +921,7 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) /* SSID */ p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, _SSID_IE_, &ie_len, (pbss_network->IELength - _BEACON_IE_OFFSET_)); if (p && ie_len > 0) { + ie_len = min_t(int, ie_len, sizeof(pbss_network->Ssid.Ssid)); memset(&pbss_network->Ssid, 0, sizeof(struct ndis_802_11_ssid)); memcpy(pbss_network->Ssid.Ssid, (p + 2), ie_len); pbss_network->Ssid.SsidLength = ie_len; @@ -939,6 +940,7 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) /* get supported rates */ p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, _SUPPORTEDRATES_IE_, &ie_len, (pbss_network->IELength - _BEACON_IE_OFFSET_)); if (p != NULL) { + ie_len = min_t(int, ie_len, NDIS_802_11_LENGTH_RATES_EX); memcpy(supportRate, p+2, ie_len); supportRateNum = ie_len; } @@ -946,6 +948,8 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) /* get ext_supported rates */ p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, _EXT_SUPPORTEDRATES_IE_, &ie_len, pbss_network->IELength - _BEACON_IE_OFFSET_); if (p != NULL) { + ie_len = min_t(int, ie_len, + NDIS_802_11_LENGTH_RATES_EX - supportRateNum); memcpy(supportRate+supportRateNum, p+2, ie_len); supportRateNum += ie_len; } @@ -1061,6 +1065,7 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) pht_cap->supp_mcs_set[0] = 0xff; pht_cap->supp_mcs_set[1] = 0x0; } + ie_len = min_t(int, ie_len, sizeof(pmlmepriv->htpriv.ht_cap)); memcpy(&pmlmepriv->htpriv.ht_cap, p+2, ie_len); }