qcacld-3.0: Validate assoc response IE len before copy

When host sends ft assoc response to supplicant, it
allocates a buffer of fixed size and copies a variable
length of assoc response IEs to this fixed sized buffer.
There is a possibility of OOB write to the allocated buffer
if the assoc response IEs length is greater than the
allocated buffer size.

To avoid above issue validate the assoc response IEs length
with the allocated buffer size before data copy to the buffer.

Change-ID: Ife9c2071a8cc4a2918b9f349f4024478f94b2d78
CRs-Fixed: 2575144

1 files changed, 11 insertions, 5 deletions

diff --git a/core/hdd/src/wlan_hdd_assoc.c b/core/hdd/src/wlan_hdd_assoc.c
index 32bb9454f378..fbc929befe0a 100644
--- a/core/hdd/src/wlan_hdd_assoc.c
+++ b/core/hdd/src/wlan_hdd_assoc.c
@@ -1073,8 +1073,9 @@ hdd_send_ft_assoc_response(struct net_device *dev,
 	unsigned int len = 0;
 	u8 *pFTAssocRsp = NULL;
 
-	if (pCsrRoamInfo->nAssocRspLength == 0) {
-		hdd_debug("assoc rsp length is 0");
+	if (pCsrRoamInfo->nAssocRspLength < FT_ASSOC_RSP_IES_OFFSET) {
+		hdd_debug("Invalid assoc rsp length %d",
+			  pCsrRoamInfo->nAssocRspLength);
 		return;
 	}
 
@@ -1091,15 +1092,20 @@ hdd_send_ft_assoc_response(struct net_device *dev,
 		   (unsigned int)pFTAssocRsp[0],
 		   (unsigned int)pFTAssocRsp[1]);
 
+	/* Send the Assoc Resp, the supplicant needs this for initial Auth. */
+	len = pCsrRoamInfo->nAssocRspLength - FT_ASSOC_RSP_IES_OFFSET;
+	if (len > IW_GENERIC_IE_MAX) {
+		hdd_err("Invalid Assoc resp length %d", len);
+		return;
+	}
+	wrqu.data.length = len;
+
 	/* We need to send the IEs to the supplicant. */
 	buff = qdf_mem_malloc(IW_GENERIC_IE_MAX);
 	if (buff == NULL) {
 		hdd_err("unable to allocate memory");
 		return;
 	}
-	/* Send the Assoc Resp, the supplicant needs this for initial Auth. */
-	len = pCsrRoamInfo->nAssocRspLength - FT_ASSOC_RSP_IES_OFFSET;
-	wrqu.data.length = len;
 	memcpy(buff, pFTAssocRsp, len);
 	wireless_send_event(dev, IWEVASSOCRESPIE, &wrqu, buff);