sysctl: sysctl_binary.c Fix compilation when !CONFIG_NET

dev_get_by_index does not exist when the network stack is not compiled in, so only include the code to follow wild card paths when the network stack is present. I have shuffled the code around a little to make it clear that dev_put is called after dev_get_by_index showing that there is no leak. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

sysctl: sysctl_binary.c Fix compilation when !CONFIG_NET
dev_get_by_index does not exist when the network stack is not compiled in, so only include the code to follow wild card paths when the network stack is present. I have shuffled the code around a little to make it clear that dev_put is called after dev_get_by_index showing that there is no leak. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Eric W. Biederman
1 parent 2fb10732c3
Showing 1 changed file with 20 additions and 15 deletions Side-by-side Diff
kernel/sysctl_binary.c
@@ -12,6 +12,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/file.h>
 #include <linux/ctype.h>
+#include <linux/netdevice.h>
  
 #ifdef CONFIG_SYSCTL_SYSCALL
  
  
@@ -1250,9 +1251,12 @@
 static const struct bin_table *get_sysctl(const int *name, int nlen, char *path)
 {
 	const struct bin_table *table = &bin_root_table[0];
-	struct net *net = current->nsproxy->net_ns;
 	int ctl_name;
  
+	/* The binary sysctl tables have a small maximum depth so
+	 * there is no danger of overflowing our path as it PATH_MAX
+	 * bytes long.
+	 */
 	memcpy(path, "sys/", 4);
 	path += 4;
  
  
  
  
  
  
@@ -1263,30 +1267,31 @@
 	name++;
 	nlen--;
 	for ( ; table->convert; table++) {
-		struct net_device *dev = NULL;
-		const char *procname = NULL;
+		int len = 0;
  
 		/* Use the well known sysctl number to proc name mapping */
-		if (ctl_name == table->ctl_name)
-			procname = table->procname;
-
+		if (ctl_name == table->ctl_name) {
+			len = strlen(table->procname);
+			memcpy(path, table->procname, len);
+		}
+#ifdef CONFIG_NET
 		/*
 		 * For a wild card entry map from ifindex to network
 		 * device name.
 		 */
 		else if (!table->ctl_name) {
+			struct net *net = current->nsproxy->net_ns;
+			struct net_device *dev;
 			dev = dev_get_by_index(net, ctl_name);
-			if (dev)
-				procname = dev->name;
+			if (dev) {
+				len = strlen(dev->name);
+				memcpy(path, dev->name, len);
+				dev_put(dev);
+			}
 		}
-		if (procname) {
-			int len;
-
-			len = strlen(procname);
-			memcpy(path, procname, len);
+#endif
+		if (len) {
 			path += len;
-			if (dev)
-				dev_put(dev);
 			if (table->child) {
 				*path++ = '/';
 				table = table->child;
...	...	@@ -12,6 +12,7 @@
12	12	#include <linux/pid_namespace.h>
13	13	#include <linux/file.h>
14	14	#include <linux/ctype.h>
	15	+#include <linux/netdevice.h>
15	16
16	17	#ifdef CONFIG_SYSCTL_SYSCALL
17	18
18	19
...	...	@@ -1250,9 +1251,12 @@
1250	1251	static const struct bin_table get_sysctl(const int name, int nlen, char *path)
1251	1252	{
1252	1253	const struct bin_table *table = &bin_root_table[0];
1253		- struct net *net = current->nsproxy->net_ns;
1254	1254	int ctl_name;
1255	1255
	1256	+ /* The binary sysctl tables have a small maximum depth so
	1257	+ * there is no danger of overflowing our path as it PATH_MAX
	1258	+ * bytes long.
	1259	+ */
1256	1260	memcpy(path, "sys/", 4);
1257	1261	path += 4;
1258	1262
1259	1263
1260	1264
1261	1265
1262	1266
1263	1267
...	...	@@ -1263,30 +1267,31 @@
1263	1267	name++;
1264	1268	nlen--;
1265	1269	for ( ; table->convert; table++) {
1266		- struct net_device *dev = NULL;
1267		- const char *procname = NULL;
	1270	+ int len = 0;
1268	1271
1269	1272	/* Use the well known sysctl number to proc name mapping */
1270		- if (ctl_name == table->ctl_name)
1271		- procname = table->procname;
1272		-
	1273	+ if (ctl_name == table->ctl_name) {
	1274	+ len = strlen(table->procname);
	1275	+ memcpy(path, table->procname, len);
	1276	+ }
	1277	+#ifdef CONFIG_NET
1273	1278	/*
1274	1279	* For a wild card entry map from ifindex to network
1275	1280	* device name.
1276	1281	*/
1277	1282	else if (!table->ctl_name) {
	1283	+ struct net *net = current->nsproxy->net_ns;
	1284	+ struct net_device *dev;
1278	1285	dev = dev_get_by_index(net, ctl_name);
1279		- if (dev)
1280		- procname = dev->name;
	1286	+ if (dev) {
	1287	+ len = strlen(dev->name);
	1288	+ memcpy(path, dev->name, len);
	1289	+ dev_put(dev);
	1290	+ }
1281	1291	}
1282		- if (procname) {
1283		- int len;
1284		-
1285		- len = strlen(procname);
1286		- memcpy(path, procname, len);
	1292	+#endif
	1293	+ if (len) {
1287	1294	path += len;
1288		- if (dev)
1289		- dev_put(dev);
1290	1295	if (table->child) {
1291	1296	*path++ = '/';
1292	1297	table = table->child;