From ab42f28d5f3471a2880e9f522964627b45a3e22e Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 5 Mar 2021 11:56:32 +0300 Subject: [PATCH] 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 --- drivers/staging/rtl8188eu/core/rtw_ap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/staging/rtl8188eu/core/rtw_ap.c b/drivers/staging/rtl8188eu/core/rtw_ap.c index 51a5b71f8c25..1c0300ce6336 100644 --- a/drivers/staging/rtl8188eu/core/rtw_ap.c +++ b/drivers/staging/rtl8188eu/core/rtw_ap.c @@ -784,6 +784,7 @@ 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->ie_length - _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.ssid_length = ie_len; @@ -802,6 +803,7 @@ 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->ie_length - _BEACON_IE_OFFSET_)); if (p) { + ie_len = min_t(int, ie_len, NDIS_802_11_LENGTH_RATES_EX); memcpy(supportRate, p + 2, ie_len); supportRateNum = ie_len; } @@ -809,6 +811,8 @@ 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->ie_length - _BEACON_IE_OFFSET_); if (p) { + ie_len = min_t(int, ie_len, + NDIS_802_11_LENGTH_RATES_EX - supportRateNum); memcpy(supportRate + supportRateNum, p + 2, ie_len); supportRateNum += ie_len; } @@ -922,6 +926,7 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) pht_cap->mcs.rx_mask[0] = 0xff; pht_cap->mcs.rx_mask[1] = 0x0; + ie_len = min_t(int, ie_len, sizeof(pmlmepriv->htpriv.ht_cap)); memcpy(&pmlmepriv->htpriv.ht_cap, p + 2, ie_len); }