[PATCH 13/30] netfilter: x_tables: add counters allocation wrapper
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2018-03-12 17:59:37
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Florian Westphal <fw@strlen.de> 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> --- 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(-)
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index fa0c19c328f1..0bd93c589a8c 100644
--- 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, const void *src, 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,
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index be5821215ea0..82ba09b50fdb 100644
--- 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, const char *name, 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;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 29bda9484a33..4901ca6c3e09 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c@@ -1045,7 +1045,7 @@ __do_replace(struct net *net, const char *name, unsigned int valid_hooks, 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;
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index ba3776a4d305..e84cec49b60f 100644
--- 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 *name, unsigned int valid_hooks, 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;
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 01f8e122e74e..82b1f8f52ac6 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c@@ -1290,6 +1290,21 @@ static int xt_jumpstack_alloc(struct xt_table_info *i) 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,
--
2.11.0