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.
Showing the changes to kernel/sysctl_binary.c (1 of 1 file). Show all
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| @@ -12,6 +12,7 @@ · 11 unmodified lines | ||
| 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 | |
| @@ -1250,9 +1251,12 @@ out: · 1232 unmodified lines | ||
| 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 | |
| @@ -1263,30 +1267,31 @@ repeat: · 4 unmodified lines | ||
| 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; |