NET: ROSE: Don't use static buffer.

The use of a static buffer in rose2asc() to return its result is not
threadproof and can result in corruption if multiple threads are trying
to use one of the procfs files based on rose2asc().

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/rose.h

@@ -156,7 +156,7 @@ extern int  sysctl_rose_maximum_vcs;
 extern int  sysctl_rose_window_size;
 extern int  rosecmp(rose_address *, rose_address *);
 extern int  rosecmpm(rose_address *, rose_address *, unsigned short);
-extern const char *rose2asc(const rose_address *);
+extern char *rose2asc(char *buf, const rose_address *);
 extern struct sock *rose_find_socket(unsigned int, struct rose_neigh *);
 extern void rose_kill_by_neigh(struct rose_neigh *);
 extern unsigned int rose_new_lci(struct rose_neigh *);

net/rose/af_rose.c

@@ -92,23 +92,21 @@ static void rose_set_lockdep_key(struct net_device *dev)
 /*
  *	Convert a ROSE address into text.
  */
-const char *rose2asc(const rose_address *addr)
+char *rose2asc(char *buf, const rose_address *addr)
 {
-	static char buffer[11];
-
 	if (addr->rose_addr[0] == 0x00 && addr->rose_addr[1] == 0x00 &&
 	    addr->rose_addr[2] == 0x00 && addr->rose_addr[3] == 0x00 &&
 	    addr->rose_addr[4] == 0x00) {
-		strcpy(buffer, "*");
+		strcpy(buf, "*");
 	} else {
-		sprintf(buffer, "%02X%02X%02X%02X%02X", addr->rose_addr[0] & 0xFF,
+		sprintf(buf, "%02X%02X%02X%02X%02X", addr->rose_addr[0] & 0xFF,
 						addr->rose_addr[1] & 0xFF,
 						addr->rose_addr[2] & 0xFF,
 						addr->rose_addr[3] & 0xFF,
 						addr->rose_addr[4] & 0xFF);
 	}
 
-	return buffer;
+	return buf;
 }
 
 /*
@@ -1437,7 +1435,7 @@ static void rose_info_stop(struct seq_file *seq, void *v)
 
 static int rose_info_show(struct seq_file *seq, void *v)
 {
-	char buf[11];
+	char buf[11], rsbuf[11];
 
 	if (v == SEQ_START_TOKEN)
 		seq_puts(seq,
@@ -1455,8 +1453,8 @@ static int rose_info_show(struct seq_file *seq, void *v)
 			devname = dev->name;
 
 		seq_printf(seq, "%-10s %-9s ",
-			rose2asc(&rose->dest_addr),
-			ax2asc(buf, &rose->dest_call));
+			   rose2asc(rsbuf, &rose->dest_addr),
+			   ax2asc(buf, &rose->dest_call));
 
 		if (ax25cmp(&rose->source_call, &null_ax25_address) == 0)
 			callsign = "??????-?";
@@ -1465,7 +1463,7 @@ static int rose_info_show(struct seq_file *seq, void *v)
 
 		seq_printf(seq,
 			   "%-10s %-9s %-5s %3.3X %05d  %d  %d  %d  %d %3lu %3lu %3lu %3lu %3lu %3lu/%03lu %5d %5d %ld\n",
-			rose2asc(&rose->source_addr),
+			rose2asc(rsbuf, &rose->source_addr),
 			callsign,
 			devname,
 			rose->lci & 0x0FFF,

net/rose/rose_route.c

@@ -1104,6 +1104,7 @@ static void rose_node_stop(struct seq_file *seq, void *v)
 
 static int rose_node_show(struct seq_file *seq, void *v)
 {
+	char rsbuf[11];
 	int i;
 
 	if (v == SEQ_START_TOKEN)
@@ -1112,13 +1113,13 @@ static int rose_node_show(struct seq_file *seq, void *v)
 		const struct rose_node *rose_node = v;
 		/* if (rose_node->loopback) {
 			seq_printf(seq, "%-10s %04d 1 loopback\n",
-				rose2asc(&rose_node->address),
-				rose_node->mask);
+				   rose2asc(rsbuf, &rose_node->address),
+				   rose_node->mask);
 		} else { */
 			seq_printf(seq, "%-10s %04d %d",
-				rose2asc(&rose_node->address),
-				rose_node->mask,
-				rose_node->count);
+				   rose2asc(rsbuf, &rose_node->address),
+				   rose_node->mask,
+				   rose_node->count);
 
 			for (i = 0; i < rose_node->count; i++)
 				seq_printf(seq, " %05d",
@@ -1267,7 +1268,7 @@ static void rose_route_stop(struct seq_file *seq, void *v)
 
 static int rose_route_show(struct seq_file *seq, void *v)
 {
-	char buf[11];
+	char buf[11], rsbuf[11];
 
 	if (v == SEQ_START_TOKEN)
 		seq_puts(seq,
@@ -1279,7 +1280,7 @@ static int rose_route_show(struct seq_file *seq, void *v)
 			seq_printf(seq,
 				   "%3.3X  %-10s  %-9s  %05d      ",
 				   rose_route->lci1,
-				   rose2asc(&rose_route->src_addr),
+				   rose2asc(rsbuf, &rose_route->src_addr),
 				   ax2asc(buf, &rose_route->src_call),
 				   rose_route->neigh1->number);
 		else
@@ -1289,10 +1290,10 @@ static int rose_route_show(struct seq_file *seq, void *v)
 		if (rose_route->neigh2)
 			seq_printf(seq,
 				   "%3.3X  %-10s  %-9s  %05d\n",
-				rose_route->lci2,
-				rose2asc(&rose_route->dest_addr),
-				ax2asc(buf, &rose_route->dest_call),
-				rose_route->neigh2->number);
+				   rose_route->lci2,
+				   rose2asc(rsbuf, &rose_route->dest_addr),
+				   ax2asc(buf, &rose_route->dest_call),
+				   rose_route->neigh2->number);
 		 else
 			 seq_puts(seq,
 				  "000  *           *          00000\n");