1 files changed, 49 insertions, 24 deletions

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 136ed7d4bd73..e79c0fbd9e89 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -393,15 +393,11 @@ ebt_check_watcher(struct ebt_entry_watcher *w, struct ebt_entry *e,
         return 0;
 }
 
-/*
- * this one is very careful, as it is the first function
- * to parse the userspace data
- */
 static inline int
-ebt_check_entry_size_and_hooks(struct ebt_entry *e,
+__ebt_verify_pointers(struct ebt_entry *e,
    struct ebt_table_info *newinfo, char *base, char *limit,
-   struct ebt_entries **hook_entries, unsigned int *n, unsigned int *cnt,
-   unsigned int *totalcnt, unsigned int *udc_cnt, unsigned int valid_hooks)
+   struct ebt_entries **hook_entries,
+   unsigned int valid_hooks)
 {
         unsigned int offset = (char *)e - newinfo->entries;
         size_t left = (limit - base) - offset;
@@ -416,8 +412,6 @@ ebt_check_entry_size_and_hooks(struct ebt_entry *e,
                 if ((char *)hook_entries[i] == base + offset)
                         break;
         }
-        /* beginning of a new chain
-           if i == NF_BR_NUMHOOKS it must be a user defined chain */
         if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
                 if (e->bitmask != 0) {
                         /* we make userspace set this right,
@@ -426,6 +420,45 @@ ebt_check_entry_size_and_hooks(struct ebt_entry *e,
                                  "in distinguisher\n");
                         return -EINVAL;
                 }
+                if (left < sizeof(struct ebt_entries))
+                        goto Esmall;
+                if (i != NF_BR_NUMHOOKS)
+                        newinfo->hook_entry[i] = (struct ebt_entries *)e;
+                return 0;
+        }
+        if (left < sizeof(struct ebt_entry))
+                goto Esmall;
+        if (left < e->next_offset)
+                goto Esmall;
+        return 0;
+
+Esmall:
+        BUGPRINT("entries_size too small\n");
+        return -EINVAL;
+}
+
+/*
+ * this one is very careful, as it is the first function
+ * to parse the userspace data
+ */
+static inline int
+ebt_check_entry_size_and_hooks(struct ebt_entry *e,
+   struct ebt_table_info *newinfo, char *base,
+   struct ebt_entries **hook_entries, unsigned int *n, unsigned int *cnt,
+   unsigned int *totalcnt, unsigned int *udc_cnt, unsigned int valid_hooks)
+{
+        unsigned int offset = (char *)e - newinfo->entries;
+        int i;
+
+        for (i = 0; i < NF_BR_NUMHOOKS; i++) {
+                if ((valid_hooks & (1 << i)) == 0)
+                        continue;
+                if ((char *)hook_entries[i] == base + offset)
+                        break;
+        }
+        /* beginning of a new chain
+           if i == NF_BR_NUMHOOKS it must be a user defined chain */
+        if (i != NF_BR_NUMHOOKS || !e->bitmask) {
                 /* this checks if the previous chain has as many entries
                    as it said it has */
                 if (*n != *cnt) {
@@ -433,9 +466,6 @@ ebt_check_entry_size_and_hooks(struct ebt_entry *e,
                                  "in the chain\n");
                         return -EINVAL;
                 }
-                /* before we look at the struct, be sure it is not too big */
-                if (left < sizeof(struct ebt_entries))
-                        goto Esmall;
                 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
                    ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
                         /* only RETURN from udc */
@@ -447,8 +477,6 @@ ebt_check_entry_size_and_hooks(struct ebt_entry *e,
                 }
                 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
                         (*udc_cnt)++;
-                else
-                        newinfo->hook_entry[i] = (struct ebt_entries *)e;
                 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
                         BUGPRINT("counter_offset != totalcnt");
                         return -EINVAL;
@@ -458,8 +486,6 @@ ebt_check_entry_size_and_hooks(struct ebt_entry *e,
                 return 0;
         }
         /* a plain old entry, heh */
-        if (left < sizeof(struct ebt_entry))
-                goto Esmall;
         if (sizeof(struct ebt_entry) > e->watchers_offset ||
            e->watchers_offset > e->target_offset ||
            e->target_offset >= e->next_offset) {
@@ -471,16 +497,9 @@ ebt_check_entry_size_and_hooks(struct ebt_entry *e,
                 BUGPRINT("target size too small\n");
                 return -EINVAL;
         }
-        if (left < e->next_offset)
-                goto Esmall;
-
         (*cnt)++;
         (*totalcnt)++;
         return 0;
-
-Esmall:
-        BUGPRINT("entries_size too small\n");
-        return -EINVAL;
 }
 
 struct ebt_cl_stack
@@ -776,6 +795,12 @@ static int translate_table(struct ebt_replace *repl,
         newinfo->entries_size = repl->entries_size;
         newinfo->nentries = repl->nentries;
 
+        ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
+           __ebt_verify_pointers, newinfo, repl->entries,
+           repl->entries + repl->entries_size, repl->hook_entry, repl->valid_hooks);
+        if (ret != 0)
+                return ret;
+
         /* do some early checkings and initialize some things */
         i = 0; /* holds the expected nr. of entries for the chain */
         j = 0; /* holds the up to now counted entries for the chain */
@@ -784,7 +809,7 @@ static int translate_table(struct ebt_replace *repl,
         udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
         ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
            ebt_check_entry_size_and_hooks, newinfo, repl->entries,
-           repl->entries + repl->entries_size, repl->hook_entry, &i, &j, &k,
+           repl->hook_entry, &i, &j, &k,
            &udc_cnt, repl->valid_hooks);
 
         if (ret != 0)