diff options
Diffstat (limited to 'net/ipv4/netfilter/arp_tables.c')
-rw-r--r-- | net/ipv4/netfilter/arp_tables.c | 303 |
1 files changed, 89 insertions, 214 deletions
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 4133b0f513af..60f5161abcb4 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -367,6 +367,18 @@ static inline bool unconditional(const struct arpt_entry *e) memcmp(&e->arp, &uncond, sizeof(uncond)) == 0; } +static bool find_jump_target(const struct xt_table_info *t, + const struct arpt_entry *target) +{ + struct arpt_entry *iter; + + xt_entry_foreach(iter, t->entries, t->size) { + if (iter == target) + return true; + } + return false; +} + /* Figures out from what hook each rule can be called: returns 0 if * there are loops. Puts hook bitmask in comefrom. */ @@ -439,6 +451,8 @@ static int mark_source_chains(const struct xt_table_info *newinfo, size = e->next_offset; e = (struct arpt_entry *) (entry0 + pos + size); + if (pos + size >= newinfo->size) + return 0; e->counters.pcnt = pos; pos += size; } else { @@ -447,20 +461,18 @@ static int mark_source_chains(const struct xt_table_info *newinfo, if (strcmp(t->target.u.user.name, XT_STANDARD_TARGET) == 0 && newpos >= 0) { - if (newpos > newinfo->size - - sizeof(struct arpt_entry)) { - duprintf("mark_source_chains: " - "bad verdict (%i)\n", - newpos); - return 0; - } - /* This a jump; chase it. */ duprintf("Jump rule %u -> %u\n", pos, newpos); + e = (struct arpt_entry *) + (entry0 + newpos); + if (!find_jump_target(newinfo, e)) + return 0; } else { /* ... this is a fallthru */ newpos = pos + e->next_offset; + if (newpos >= newinfo->size) + return 0; } e = (struct arpt_entry *) (entry0 + newpos); @@ -474,23 +486,6 @@ next: return 1; } -static inline int check_entry(const struct arpt_entry *e) -{ - const struct xt_entry_target *t; - - if (!arp_checkentry(&e->arp)) - return -EINVAL; - - if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset) - return -EINVAL; - - t = arpt_get_target_c(e); - if (e->target_offset + t->u.target_size > e->next_offset) - return -EINVAL; - - return 0; -} - static inline int check_target(struct arpt_entry *e, const char *name) { struct xt_entry_target *t = arpt_get_target(e); @@ -586,7 +581,11 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e, return -EINVAL; } - err = check_entry(e); + if (!arp_checkentry(&e->arp)) + return -EINVAL; + + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (err) return err; @@ -691,10 +690,8 @@ static int translate_table(struct xt_table_info *newinfo, void *entry0, } } - if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) { - duprintf("Looping hook\n"); + if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) return -ELOOP; - } /* Finally, each sanity check must pass */ i = 0; @@ -1126,55 +1123,17 @@ static int do_add_counters(struct net *net, const void __user *user, unsigned int i; struct xt_counters_info tmp; struct xt_counters *paddc; - unsigned int num_counters; - const char *name; - int size; - void *ptmp; struct xt_table *t; const struct xt_table_info *private; int ret = 0; struct arpt_entry *iter; unsigned int addend; -#ifdef CONFIG_COMPAT - struct compat_xt_counters_info compat_tmp; - - if (compat) { - ptmp = &compat_tmp; - size = sizeof(struct compat_xt_counters_info); - } else -#endif - { - ptmp = &tmp; - size = sizeof(struct xt_counters_info); - } - - if (copy_from_user(ptmp, user, size) != 0) - return -EFAULT; - -#ifdef CONFIG_COMPAT - if (compat) { - num_counters = compat_tmp.num_counters; - name = compat_tmp.name; - } else -#endif - { - num_counters = tmp.num_counters; - name = tmp.name; - } - if (len != size + num_counters * sizeof(struct xt_counters)) - return -EINVAL; - - paddc = vmalloc(len - size); - if (!paddc) - return -ENOMEM; + paddc = xt_copy_counters_from_user(user, len, &tmp, compat); + if (IS_ERR(paddc)) + return PTR_ERR(paddc); - if (copy_from_user(paddc, user + size, len - size) != 0) { - ret = -EFAULT; - goto free; - } - - t = xt_find_table_lock(net, NFPROTO_ARP, name); + t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name); if (IS_ERR_OR_NULL(t)) { ret = t ? PTR_ERR(t) : -ENOENT; goto free; @@ -1182,7 +1141,7 @@ static int do_add_counters(struct net *net, const void __user *user, local_bh_disable(); private = t->private; - if (private->number != num_counters) { + if (private->number != tmp.num_counters) { ret = -EINVAL; goto unlock_up_free; } @@ -1209,6 +1168,18 @@ static int do_add_counters(struct net *net, const void __user *user, } #ifdef CONFIG_COMPAT +struct compat_arpt_replace { + char name[XT_TABLE_MAXNAMELEN]; + u32 valid_hooks; + u32 num_entries; + u32 size; + u32 hook_entry[NF_ARP_NUMHOOKS]; + u32 underflow[NF_ARP_NUMHOOKS]; + u32 num_counters; + compat_uptr_t counters; + struct compat_arpt_entry entries[0]; +}; + static inline void compat_release_entry(struct compat_arpt_entry *e) { struct xt_entry_target *t; @@ -1217,20 +1188,17 @@ static inline void compat_release_entry(struct compat_arpt_entry *e) module_put(t->u.kernel.target->me); } -static inline int +static int check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, struct xt_table_info *newinfo, unsigned int *size, const unsigned char *base, - const unsigned char *limit, - const unsigned int *hook_entries, - const unsigned int *underflows, - const char *name) + const unsigned char *limit) { struct xt_entry_target *t; struct xt_target *target; unsigned int entry_offset; - int ret, off, h; + int ret, off; duprintf("check_compat_entry_size_and_hooks %p\n", e); if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 || @@ -1247,8 +1215,11 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, return -EINVAL; } - /* For purposes of check_entry casting the compat entry is fine */ - ret = check_entry((struct arpt_entry *)e); + if (!arp_checkentry(&e->arp)) + return -EINVAL; + + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (ret) return ret; @@ -1272,17 +1243,6 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, if (ret) goto release_target; - /* Check hooks & underflows */ - for (h = 0; h < NF_ARP_NUMHOOKS; h++) { - if ((unsigned char *)e - base == hook_entries[h]) - newinfo->hook_entry[h] = hook_entries[h]; - if ((unsigned char *)e - base == underflows[h]) - newinfo->underflow[h] = underflows[h]; - } - - /* Clear counters and comefrom */ - memset(&e->counters, 0, sizeof(e->counters)); - e->comefrom = 0; return 0; release_target: @@ -1291,18 +1251,17 @@ out: return ret; } -static int +static void compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, - unsigned int *size, const char *name, + unsigned int *size, struct xt_table_info *newinfo, unsigned char *base) { struct xt_entry_target *t; struct xt_target *target; struct arpt_entry *de; unsigned int origsize; - int ret, h; + int h; - ret = 0; origsize = *size; de = (struct arpt_entry *)*dstptr; memcpy(de, e, sizeof(struct arpt_entry)); @@ -1323,148 +1282,82 @@ compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, if ((unsigned char *)de - base < newinfo->underflow[h]) newinfo->underflow[h] -= origsize - *size; } - return ret; } -static int translate_compat_table(const char *name, - unsigned int valid_hooks, - struct xt_table_info **pinfo, +static int translate_compat_table(struct xt_table_info **pinfo, void **pentry0, - unsigned int total_size, - unsigned int number, - unsigned int *hook_entries, - unsigned int *underflows) + const struct compat_arpt_replace *compatr) { unsigned int i, j; struct xt_table_info *newinfo, *info; void *pos, *entry0, *entry1; struct compat_arpt_entry *iter0; - struct arpt_entry *iter1; + struct arpt_replace repl; unsigned int size; int ret = 0; info = *pinfo; entry0 = *pentry0; - size = total_size; - info->number = number; - - /* Init all hooks to impossible value. */ - for (i = 0; i < NF_ARP_NUMHOOKS; i++) { - info->hook_entry[i] = 0xFFFFFFFF; - info->underflow[i] = 0xFFFFFFFF; - } + size = compatr->size; + info->number = compatr->num_entries; duprintf("translate_compat_table: size %u\n", info->size); j = 0; xt_compat_lock(NFPROTO_ARP); - xt_compat_init_offsets(NFPROTO_ARP, number); + xt_compat_init_offsets(NFPROTO_ARP, compatr->num_entries); /* Walk through entries, checking offsets. */ - xt_entry_foreach(iter0, entry0, total_size) { + xt_entry_foreach(iter0, entry0, compatr->size) { ret = check_compat_entry_size_and_hooks(iter0, info, &size, entry0, - entry0 + total_size, - hook_entries, - underflows, - name); + entry0 + compatr->size); if (ret != 0) goto out_unlock; ++j; } ret = -EINVAL; - if (j != number) { + if (j != compatr->num_entries) { duprintf("translate_compat_table: %u not %u entries\n", - j, number); + j, compatr->num_entries); goto out_unlock; } - /* Check hooks all assigned */ - for (i = 0; i < NF_ARP_NUMHOOKS; i++) { - /* Only hooks which are valid */ - if (!(valid_hooks & (1 << i))) - continue; - if (info->hook_entry[i] == 0xFFFFFFFF) { - duprintf("Invalid hook entry %u %u\n", - i, hook_entries[i]); - goto out_unlock; - } - if (info->underflow[i] == 0xFFFFFFFF) { - duprintf("Invalid underflow %u %u\n", - i, underflows[i]); - goto out_unlock; - } - } - ret = -ENOMEM; newinfo = xt_alloc_table_info(size); if (!newinfo) goto out_unlock; - newinfo->number = number; + newinfo->number = compatr->num_entries; for (i = 0; i < NF_ARP_NUMHOOKS; i++) { newinfo->hook_entry[i] = info->hook_entry[i]; newinfo->underflow[i] = info->underflow[i]; } entry1 = newinfo->entries; pos = entry1; - size = total_size; - xt_entry_foreach(iter0, entry0, total_size) { - ret = compat_copy_entry_from_user(iter0, &pos, &size, - name, newinfo, entry1); - if (ret != 0) - break; - } + size = compatr->size; + xt_entry_foreach(iter0, entry0, compatr->size) + compat_copy_entry_from_user(iter0, &pos, &size, + newinfo, entry1); + + /* all module references in entry0 are now gone */ + xt_compat_flush_offsets(NFPROTO_ARP); xt_compat_unlock(NFPROTO_ARP); - if (ret) - goto free_newinfo; - ret = -ELOOP; - if (!mark_source_chains(newinfo, valid_hooks, entry1)) - goto free_newinfo; + memcpy(&repl, compatr, sizeof(*compatr)); - i = 0; - xt_entry_foreach(iter1, entry1, newinfo->size) { - iter1->counters.pcnt = xt_percpu_counter_alloc(); - if (IS_ERR_VALUE(iter1->counters.pcnt)) { - ret = -ENOMEM; - break; - } - - ret = check_target(iter1, name); - if (ret != 0) { - xt_percpu_counter_free(iter1->counters.pcnt); - break; - } - ++i; - if (strcmp(arpt_get_target(iter1)->u.user.name, - XT_ERROR_TARGET) == 0) - ++newinfo->stacksize; - } - if (ret) { - /* - * The first i matches need cleanup_entry (calls ->destroy) - * because they had called ->check already. The other j-i - * entries need only release. - */ - int skip = i; - j -= i; - xt_entry_foreach(iter0, entry0, newinfo->size) { - if (skip-- > 0) - continue; - if (j-- == 0) - break; - compat_release_entry(iter0); - } - xt_entry_foreach(iter1, entry1, newinfo->size) { - if (i-- == 0) - break; - cleanup_entry(iter1); - } - xt_free_table_info(newinfo); - return ret; + for (i = 0; i < NF_ARP_NUMHOOKS; i++) { + repl.hook_entry[i] = newinfo->hook_entry[i]; + repl.underflow[i] = newinfo->underflow[i]; } + repl.num_counters = 0; + repl.counters = NULL; + repl.size = newinfo->size; + ret = translate_table(newinfo, entry1, &repl); + if (ret) + goto free_newinfo; + *pinfo = newinfo; *pentry0 = entry1; xt_free_table_info(info); @@ -1472,31 +1365,18 @@ static int translate_compat_table(const char *name, free_newinfo: xt_free_table_info(newinfo); -out: - xt_entry_foreach(iter0, entry0, total_size) { + return ret; +out_unlock: + xt_compat_flush_offsets(NFPROTO_ARP); + xt_compat_unlock(NFPROTO_ARP); + xt_entry_foreach(iter0, entry0, compatr->size) { if (j-- == 0) break; compat_release_entry(iter0); } return ret; -out_unlock: - xt_compat_flush_offsets(NFPROTO_ARP); - xt_compat_unlock(NFPROTO_ARP); - goto out; } -struct compat_arpt_replace { - char name[XT_TABLE_MAXNAMELEN]; - u32 valid_hooks; - u32 num_entries; - u32 size; - u32 hook_entry[NF_ARP_NUMHOOKS]; - u32 underflow[NF_ARP_NUMHOOKS]; - u32 num_counters; - compat_uptr_t counters; - struct compat_arpt_entry entries[0]; -}; - static int compat_do_replace(struct net *net, void __user *user, unsigned int len) { @@ -1510,8 +1390,6 @@ static int compat_do_replace(struct net *net, void __user *user, return -EFAULT; /* overflow check */ - if (tmp.size >= INT_MAX / num_possible_cpus()) - return -ENOMEM; if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; if (tmp.num_counters == 0) @@ -1529,10 +1407,7 @@ static int compat_do_replace(struct net *net, void __user *user, goto free_newinfo; } - ret = translate_compat_table(tmp.name, tmp.valid_hooks, - &newinfo, &loc_cpu_entry, tmp.size, - tmp.num_entries, tmp.hook_entry, - tmp.underflow); + ret = translate_compat_table(&newinfo, &loc_cpu_entry, &tmp); if (ret != 0) goto free_newinfo; |