diff options
Diffstat (limited to 'net/netfilter')
-rw-r--r-- | net/netfilter/x_tables.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 582c9cf..1f44bfa 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -541,6 +541,40 @@ int xt_compat_match_to_user(const struct xt_entry_match *m, EXPORT_SYMBOL_GPL(xt_compat_match_to_user); #endif /* CONFIG_COMPAT */ +/** + * xt_check_entry_offsets - validate arp/ip/ip6t_entry + * + * @base: pointer to arp/ip/ip6t_entry + * @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. + * + * 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 + * length. + * + * Return: 0 on success, negative errno on failure. + */ +int xt_check_entry_offsets(const void *base, + unsigned int target_offset, + unsigned int next_offset) +{ + const struct xt_entry_target *t; + const char *e = base; + + if (target_offset + sizeof(*t) > next_offset) + return -EINVAL; + + t = (void *)(e + target_offset); + if (target_offset + t->u.target_size > next_offset) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL(xt_check_entry_offsets); + int xt_check_target(struct xt_tgchk_param *par, unsigned int size, u_int8_t proto, bool inv_proto) { |