1 files changed, 13 insertions, 24 deletions

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 44ff3f3810fa..06438fa2b1e5 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -8,6 +8,7 @@
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/socket.h>
@@ -97,25 +98,17 @@ static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
 */
 static inline u16 genl_generate_id(void)
 {
-        static u16 id_gen_idx;
-        int overflowed = 0;
+        static u16 id_gen_idx = GENL_MIN_ID;
+        int i;
 
-        do {
-                if (id_gen_idx == 0)
+        for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) {
+                if (!genl_family_find_byid(id_gen_idx))
+                        return id_gen_idx;
+                if (++id_gen_idx > GENL_MAX_ID)
                         id_gen_idx = GENL_MIN_ID;
+        }
 
-                if (++id_gen_idx > GENL_MAX_ID) {
-                        if (!overflowed) {
-                                overflowed = 1;
-                                id_gen_idx = 0;
-                                continue;
-                        } else
-                                return 0;
-                }
-
-        } while (genl_family_find_byid(id_gen_idx));
-
-        return id_gen_idx;
+        return 0;
 }
 
 static struct genl_multicast_group notify_grp;
@@ -374,11 +367,6 @@ int genl_register_family(struct genl_family *family)
                 goto errout_locked;
         }
 
-        if (genl_family_find_byid(family->id)) {
-                err = -EEXIST;
-                goto errout_locked;
-        }
-
         if (family->id == GENL_ID_GENERATE) {
                 u16 newid = genl_generate_id();
 
@@ -388,6 +376,9 @@ int genl_register_family(struct genl_family *family)
                 }
 
                 family->id = newid;
+        } else if (genl_family_find_byid(family->id)) {
+                err = -EEXIST;
+                goto errout_locked;
         }
 
         if (family->maxattr) {
@@ -691,9 +682,7 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
         int chains_to_skip = cb->args[0];
         int fams_to_skip = cb->args[1];
 
-        for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
-                if (i < chains_to_skip)
-                        continue;
+        for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
                 n = 0;
                 list_for_each_entry(rt, genl_family_chain(i), family_list) {
                         if (!rt->netnsok && !net_eq(net, &init_net))