diff options
| -rw-r--r-- | include/linux/netfilter/x_tables.h | 4 | ||||
| -rw-r--r-- | net/ipv4/netfilter/arp_tables.c | 5 | ||||
| -rw-r--r-- | net/ipv4/netfilter/ip_tables.c | 5 | ||||
| -rw-r--r-- | net/ipv6/netfilter/ip6_tables.c | 5 | ||||
| -rw-r--r-- | net/netfilter/x_tables.c | 17 |
5 files changed, 26 insertions, 10 deletions
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 08de48bbe92e..30cfb1e943fb 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -242,7 +242,7 @@ void xt_unregister_match(struct xt_match *target); int xt_register_matches(struct xt_match *match, unsigned int n); void xt_unregister_matches(struct xt_match *match, unsigned int n); -int xt_check_entry_offsets(const void *base, +int xt_check_entry_offsets(const void *base, const char *elems, unsigned int target_offset, unsigned int next_offset); @@ -494,7 +494,7 @@ void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr, unsigned int *size); int xt_compat_target_to_user(const struct xt_entry_target *t, void __user **dstptr, unsigned int *size); -int xt_compat_check_entry_offsets(const void *base, +int xt_compat_check_entry_offsets(const void *base, const char *elems, unsigned int target_offset, unsigned int next_offset); diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index ab8952a49bfa..95ed4e454c60 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -592,7 +592,8 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e, if (!arp_checkentry(&e->arp)) return -EINVAL; - err = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (err) return err; @@ -1254,7 +1255,7 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, if (!arp_checkentry(&e->arp)) return -EINVAL; - ret = xt_compat_check_entry_offsets(e, e->target_offset, + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 7d24c872723f..baab033d74e0 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -754,7 +754,8 @@ check_entry_size_and_hooks(struct ipt_entry *e, if (!ip_checkentry(&e->ip)) return -EINVAL; - err = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (err) return err; @@ -1513,7 +1514,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e, if (!ip_checkentry(&e->ip)) return -EINVAL; - ret = xt_compat_check_entry_offsets(e, + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 73eee7b5fd60..6957627c7931 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -766,7 +766,8 @@ check_entry_size_and_hooks(struct ip6t_entry *e, if (!ip6_checkentry(&e->ipv6)) return -EINVAL; - err = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (err) return err; @@ -1525,7 +1526,7 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, if (!ip6_checkentry(&e->ipv6)) return -EINVAL; - ret = xt_compat_check_entry_offsets(e, + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 1cb7a271c024..e2a6f2a9051b 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -546,14 +546,17 @@ struct compat_xt_standard_target { compat_uint_t verdict; }; -/* see xt_check_entry_offsets */ -int xt_compat_check_entry_offsets(const void *base, +int xt_compat_check_entry_offsets(const void *base, const char *elems, unsigned int target_offset, unsigned int next_offset) { + long size_of_base_struct = elems - (const char *)base; const struct compat_xt_entry_target *t; const char *e = base; + if (target_offset < size_of_base_struct) + return -EINVAL; + if (target_offset + sizeof(*t) > next_offset) return -EINVAL; @@ -577,12 +580,16 @@ EXPORT_SYMBOL(xt_compat_check_entry_offsets); * xt_check_entry_offsets - validate arp/ip/ip6t_entry * * @base: pointer to arp/ip/ip6t_entry + * @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems * @target_offset: the arp/ip/ip6_t->target_offset * @next_offset: the arp/ip/ip6_t->next_offset * * validates that target_offset and next_offset are sane. * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version. * + * This function does not validate the targets or matches themselves, it + * only tests that all the offsets and sizes are correct. + * * The arp/ip/ip6t_entry structure @base must have passed following tests: * - it must point to a valid memory location * - base to base + next_offset must be accessible, i.e. not exceed allocated @@ -591,12 +598,18 @@ EXPORT_SYMBOL(xt_compat_check_entry_offsets); * Return: 0 on success, negative errno on failure. */ int xt_check_entry_offsets(const void *base, + const char *elems, unsigned int target_offset, unsigned int next_offset) { + long size_of_base_struct = elems - (const char *)base; const struct xt_entry_target *t; const char *e = base; + /* target start is within the ip/ip6/arpt_entry struct */ + if (target_offset < size_of_base_struct) + return -EINVAL; + if (target_offset + sizeof(*t) > next_offset) return -EINVAL; |