qcacmn: Add sanity check for pktlog msgs

Add sanity check for pktlog messages, as we have seen a single case
of inconsisten nbuf. Assert if fails.

Change-Id: I6a076c4dfaa2ff8e1972dd795cadeca1302b2c0e
CRs-Fixed: 2131952

utils/pktlog/pktlog_ac.c

@@ -741,6 +741,17 @@ void pktlog_process_fw_msg(uint32_t *buff)
 }
 
 #if defined(QCA_WIFI_3_0_ADRASTEA)
+static inline int pktlog_nbuf_check_sanity(qdf_nbuf_t nbuf)
+{
+	int rc = 0; /* sane */
+
+	if ((!nbuf) ||
+	    (nbuf->data < nbuf->head) ||
+	    ((nbuf->data + skb_headlen(nbuf)) > skb_end_pointer(nbuf)))
+		rc = -EINVAL;
+
+	return rc;
+}
 /**
  * pktlog_t2h_msg_handler() - Target to host message handler
  * @context: pdev context
@@ -754,6 +765,15 @@ static void pktlog_t2h_msg_handler(void *context, HTC_PACKET *pkt)
 	qdf_nbuf_t pktlog_t2h_msg = (qdf_nbuf_t) pkt->pPktContext;
 	uint32_t *msg_word;
 
+	/* check for sanity of the packet, have seen corrupted pkts */
+	if (pktlog_nbuf_check_sanity(pktlog_t2h_msg)) {
+		qdf_print("%s: packet 0x%p corrupted? Leaking...",
+			  __func__, pktlog_t2h_msg);
+		/* do not free; may crash! */
+		QDF_ASSERT(0);
+		return;
+	}
+
 	/* check for successful message reception */
 	if (pkt->Status != QDF_STATUS_SUCCESS) {
 		if (pkt->Status != QDF_STATUS_E_CANCELED)