On Fri, Jul 30, 2021 at 08:14:52PM +0200, Fabio M. De Francesco wrote:

 static inline void __nat25_generate_ipx_network_addr_with_socket(unsigned char *networkAddr,
-				unsigned int *ipxNetAddr, unsigned short *ipxSocketAddr)
+				__be32 *ipxNetAddr, __be16 *ipxSocketAddr)
 {
+	union {
+		unsigned int f0;
+		unsigned char f1[4];
+	} addr;
+
 	memset(networkAddr, 0, MAX_NETWORK_ADDR_LEN);
 
 	networkAddr[0] = NAT25_IPX;
-	memcpy(networkAddr+1, (unsigned char *)ipxNetAddr, 4);
-	memcpy(networkAddr+5, (unsigned char *)ipxSocketAddr, 2);
+	addr.f0 = be32_to_cpu(*ipxNetAddr);
+	memcpy(networkAddr+1, addr.f1, 4);
+	addr.f0 ^= addr.f0;
+	addr.f0 = be16_to_cpu(*ipxSocketAddr);
+	memcpy(networkAddr+5, addr.f1, 2);

Here is another bug which was obscured/caused by the union.

	addr.f0 = be16_to_cpu(*ipxSocketAddr);

The addr.f0 variable is an int.  On big endian systems only the last two
bytes are set:

	memcpy(networkAddr+5, addr.f1, 2);

So this is the equivalent of:

	memset(networkAddr+5, 0, 2);

regards,
dan carpenter