This is a note to let you know that I've just added the patch titled staging: rtl8188eu: fix potential memory corruption in to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 2b5d923c01cf6abf0ae2768891421612452d2ffa Mon Sep 17 00:00:00 2001 From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Fri, 5 Mar 2021 11:56:32 +0300 Subject: staging: rtl8188eu: fix potential memory corruption in rtw_check_beacon_data() 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 <dan.carpenter@xxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/YEHyQCrFZKTXyT7J@mwanda Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 fa1e34a0d456..182bb944c9b3 100644 --- a/drivers/staging/rtl8188eu/core/rtw_ap.c +++ b/drivers/staging/rtl8188eu/core/rtw_ap.c @@ -791,6 +791,7 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, WLAN_EID_SSID, &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; @@ -811,6 +812,7 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, WLAN_EID_SUPP_RATES, &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; } @@ -819,6 +821,8 @@ int rtw_check_beacon_data(struct adapter *padapter, u8 *pbuf, int len) p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, WLAN_EID_EXT_SUPP_RATES, &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; } @@ -934,6 +938,7 @@ 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); } -- 2.30.1