@@ -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;
This is a note to let you know that I have just added a patch titled netfilter: xt_socket: fix a stack corruption bug to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt19. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 667d697af02e8e844626e5d0de63b3ace1e24bdb Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet@google.com> Date: Sun, 15 Feb 2015 19:03:45 -0800 Subject: 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: Kamal Mostafa <kamal@canonical.com> --- net/netfilter/xt_socket.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) -- 1.9.1