diff options
| author | hannes@stressinduktion.org <hannes@stressinduktion.org> | 2015-04-01 17:07:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-04-29 10:31:46 +0200 |
| commit | c91f81773cd4bbebfe744e9ab30a7ce093f9b930 (patch) | |
| tree | a21775dbb33156bef196464337e9f38059e8f10d /include/net | |
| parent | e6250f868ccc8a609c88524a785a6e0d915ad3cb (diff) | |
ipv6: protect skb->sk accesses from recursive dereference inside the stack
[ Upstream commit f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 ]
We should not consult skb->sk for output decisions in xmit recursion
levels > 0 in the stack. Otherwise local socket settings could influence
the result of e.g. tunnel encapsulation process.
ipv6 does not conform with this in three places:
1) ip6_fragment: we do consult ipv6_npinfo for frag_size
2) sk_mc_loop in ipv6 uses skb->sk and checks if we should
loop the packet back to the local socket
3) ip6_skb_dst_mtu could query the settings from the user socket and
force a wrong MTU
Furthermore:
In sk_mc_loop we could potentially land in WARN_ON(1) if we use a
PF_PACKET socket ontop of an IPv6-backed vxlan device.
Reuse xmit_recursion as we are currently only interested in protecting
tunnel devices.
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/ip.h | 16 | ||||
| -rw-r--r-- | include/net/ip6_route.h | 3 | ||||
| -rw-r--r-- | include/net/sock.h | 2 |
3 files changed, 4 insertions, 17 deletions
diff --git a/include/net/ip.h b/include/net/ip.h index 3446cdd29608..5128fa7a8302 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -407,22 +407,6 @@ static __inline__ void inet_reset_saddr(struct sock *sk) #endif -static inline int sk_mc_loop(struct sock *sk) -{ - if (!sk) - return 1; - switch (sk->sk_family) { - case AF_INET: - return inet_sk(sk)->mc_loop; -#if IS_ENABLED(CONFIG_IPV6) - case AF_INET6: - return inet6_sk(sk)->mc_loop; -#endif - } - WARN_ON(1); - return 1; -} - bool ip_call_ra_chain(struct sk_buff *skb); /* diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 2e74c6cfa612..ee2d53ae62fe 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -168,7 +168,8 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); static inline int ip6_skb_dst_mtu(struct sk_buff *skb) { - struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; + struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? + inet6_sk(skb->sk) : NULL; return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ? skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); diff --git a/include/net/sock.h b/include/net/sock.h index f66b2b19a6e4..0c79a740e97d 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1815,6 +1815,8 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); +bool sk_mc_loop(struct sock *sk); + static inline bool sk_can_gso(const struct sock *sk) { return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); |