diff options
| -rw-r--r-- | net/bridge/netfilter/ebtables.c | 73 |
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) |