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authorEric Dumazet <edumazet@google.com>2015-02-15 19:03:45 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-26 15:06:59 +0100
commit2e1a691e057140b6b559e885b2876581dc249489 (patch)
treea234e97b3718659b0a4a4cc62aecaa8351d255bf /net
parent17ad69a74cea38b94148cb7449d9a6c682d04444 (diff)
downloadlinux-linaro-stable-2e1a691e057140b6b559e885b2876581dc249489.tar.gz
netfilter: xt_socket: fix a stack corruption bug
commit 78296c97ca1fd3b104f12e1f1fbc06c46635990b upstream. As soon as extract_icmp6_fields() returns, its local storage (automatic variables) is deallocated and can be overwritten. Lets add an additional parameter to make sure storage is valid long enough. While we are at it, adds some const qualifiers. Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: b64c9256a9b76 ("tproxy: added IPv6 support to the socket match") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/xt_socket.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index 1ba67931eb1b..13332dbf291d 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -243,12 +243,13 @@ static int
extract_icmp6_fields(const struct sk_buff *skb,
unsigned int outside_hdrlen,
int *protocol,
- struct in6_addr **raddr,
- struct in6_addr **laddr,
+ const struct in6_addr **raddr,
+ const struct in6_addr **laddr,
__be16 *rport,
- __be16 *lport)
+ __be16 *lport,
+ struct ipv6hdr *ipv6_var)
{
- struct ipv6hdr *inside_iph, _inside_iph;
+ const struct ipv6hdr *inside_iph;
struct icmp6hdr *icmph, _icmph;
__be16 *ports, _ports[2];
u8 inside_nexthdr;
@@ -263,12 +264,14 @@ extract_icmp6_fields(const struct sk_buff *skb,
if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK)
return 1;
- inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph), sizeof(_inside_iph), &_inside_iph);
+ inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph),
+ sizeof(*ipv6_var), ipv6_var);
if (inside_iph == NULL)
return 1;
inside_nexthdr = inside_iph->nexthdr;
- inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) + sizeof(_inside_iph),
+ inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) +
+ sizeof(*ipv6_var),
&inside_nexthdr, &inside_fragoff);
if (inside_hdrlen < 0)
return 1; /* hjm: Packet has no/incomplete transport layer headers. */
@@ -315,10 +318,10 @@ xt_socket_get_sock_v6(struct net *net, const u8 protocol,
static bool
socket_mt6_v1_v2(const struct sk_buff *skb, struct xt_action_param *par)
{
- struct ipv6hdr *iph = ipv6_hdr(skb);
+ struct ipv6hdr ipv6_var, *iph = ipv6_hdr(skb);
struct udphdr _hdr, *hp = NULL;
struct sock *sk = skb->sk;
- struct in6_addr *daddr = NULL, *saddr = NULL;
+ const struct in6_addr *daddr = NULL, *saddr = NULL;
__be16 uninitialized_var(dport), uninitialized_var(sport);
int thoff = 0, uninitialized_var(tproto);
const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
@@ -342,7 +345,7 @@ socket_mt6_v1_v2(const struct sk_buff *skb, struct xt_action_param *par)
} else if (tproto == IPPROTO_ICMPV6) {
if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr,
- &sport, &dport))
+ &sport, &dport, &ipv6_var))
return false;
} else {
return false;