4.14-stable review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
commit c84ca954ac9fa67a6ce27f91f01e4451c74fd8f6 upstream.
allows to have size checks in a single spot. This is supposed to reduce oom situations when fuzz-testing xtables.
Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/netfilter/x_tables.h | 1 + net/ipv4/netfilter/arp_tables.c | 2 +- net/ipv4/netfilter/ip_tables.c | 2 +- net/ipv6/netfilter/ip6_tables.c | 2 +- net/netfilter/x_tables.c | 15 +++++++++++++++ 5 files changed, 19 insertions(+), 3 deletions(-)
--- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -301,6 +301,7 @@ int xt_data_to_user(void __user *dst, co
void *xt_copy_counters_from_user(const void __user *user, unsigned int len, struct xt_counters_info *info, bool compat); +struct xt_counters *xt_counters_alloc(unsigned int counters);
struct xt_table *xt_register_table(struct net *net, const struct xt_table *table, --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -883,7 +883,7 @@ static int __do_replace(struct net *net, struct arpt_entry *iter;
ret = 0; - counters = vzalloc(num_counters * sizeof(struct xt_counters)); + counters = xt_counters_alloc(num_counters); if (!counters) { ret = -ENOMEM; goto out; --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1044,7 +1044,7 @@ __do_replace(struct net *net, const char struct ipt_entry *iter;
ret = 0; - counters = vzalloc(num_counters * sizeof(struct xt_counters)); + counters = xt_counters_alloc(num_counters); if (!counters) { ret = -ENOMEM; goto out; --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1063,7 +1063,7 @@ __do_replace(struct net *net, const char struct ip6t_entry *iter;
ret = 0; - counters = vzalloc(num_counters * sizeof(struct xt_counters)); + counters = xt_counters_alloc(num_counters); if (!counters) { ret = -ENOMEM; goto out; --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -1187,6 +1187,21 @@ static int xt_jumpstack_alloc(struct xt_ return 0; }
+struct xt_counters *xt_counters_alloc(unsigned int counters) +{ + struct xt_counters *mem; + + if (counters == 0 || counters > INT_MAX / sizeof(*mem)) + return NULL; + + counters *= sizeof(*mem); + if (counters > XT_MAX_TABLE_SIZE) + return NULL; + + return vzalloc(counters); +} +EXPORT_SYMBOL(xt_counters_alloc); + struct xt_table_info * xt_replace_table(struct xt_table *table, unsigned int num_counters,