netfilter: ensure number of counters is >0 in do_replace()

commit 1086bbe97a074844188c6c988fa0b1a98c3ccbb9 upstream.

After improving setsockopt() coverage in trinity, I started triggering
vmalloc failures pretty reliably from this code path:

warn_alloc_failed+0xe9/0x140
__vmalloc_node_range+0x1be/0x270
vzalloc+0x4b/0x50
__do_replace+0x52/0x260 [ip_tables]
do_ipt_set_ctl+0x15d/0x1d0 [ip_tables]
nf_setsockopt+0x65/0x90
ip_setsockopt+0x61/0xa0
raw_setsockopt+0x16/0x60
sock_common_setsockopt+0x14/0x20
SyS_setsockopt+0x71/0xd0

It turns out we don't validate that the num_counters field in the
struct we pass in from userspace is initialized.

The same problem also exists in ebtables, arptables, ipv6, and the
compat variants.

Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 1059ed3bc2557d597cb0548962a888e544d74a67..42ee65e1bc7f938640a0e1a86141cbfaf3b5c201 100644 (file)
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1105,6 +1105,8 @@ static int do_replace(struct net *net, const void __user *user,
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
 
        tmp.name[sizeof(tmp.name) - 1] = 0;
 
@@ -2150,6 +2152,8 @@ static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
 
        memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
 

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index fc5147cec3b70159b1f747cf8bae272d1253d7f1..3bdb46b325ab528205f04db042e515ae2875d450 100644 (file)
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1065,6 +1065,9 @@ static int do_replace(struct net *net, const void __user *user,
        /* overflow check */
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);
@@ -1375,6 +1378,9 @@ static int compat_do_replace(struct net *net, void __user *user,
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 374e977674b655e88f5101dcf88c30ad8a0a1ac7..baa1f65e5142353b323297ca52275a4bf0a1e930 100644 (file)
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1251,6 +1251,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
        /* overflow check */
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);
@@ -1652,6 +1655,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 2f41e0b9472f7d7b881f8ac8c7695506a4b27a39..9802b24696625defdeee3c1b7552aa2f875ae35e 100644 (file)
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1261,6 +1261,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
        /* overflow check */
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);
@@ -1655,6 +1658,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);