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authorHerbert Xu <herbert@gondor.apana.org.au>2010-07-05 14:50:08 +0000
committerDavid S. Miller <davem@davemloft.net>2010-07-05 20:08:06 -0700
commit7f285fa78d4b81b8458f05e77fb6b46245121b4e (patch)
treea4fa0d8e5cd102bb3aed7ad984de31e8a5f7575e
parentbcfcc450baaaa44afc1d3c51ef96a53338ff0eb2 (diff)
downloadlinux-7f285fa78d4b81b8458f05e77fb6b46245121b4e.tar.bz2
bridge br_multicast: BUG: unable to handle kernel NULL pointer dereference
On Tue, Jul 06, 2010 at 08:48:35AM +0800, Herbert Xu wrote: > > bridge: Restore NULL check in br_mdb_ip_get Resend with proper attribution. bridge: Restore NULL check in br_mdb_ip_get Somewhere along the line the NULL check in br_mdb_ip_get went AWOL, causing crashes when we receive an IGMP packet with no multicast table allocated. This patch restores it and ensures all br_mdb_*_get functions use it. Reported-by: Frank Arnold <frank.arnold@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Thanks, Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/bridge/br_multicast.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 9d21d98ae5fa..27ae946363f1 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -99,6 +99,15 @@ static struct net_bridge_mdb_entry *__br_mdb_ip_get(
return NULL;
}
+static struct net_bridge_mdb_entry *br_mdb_ip_get(
+ struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
+{
+ if (!mdb)
+ return NULL;
+
+ return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
+}
+
static struct net_bridge_mdb_entry *br_mdb_ip4_get(
struct net_bridge_mdb_htable *mdb, __be32 dst)
{
@@ -107,7 +116,7 @@ static struct net_bridge_mdb_entry *br_mdb_ip4_get(
br_dst.u.ip4 = dst;
br_dst.proto = htons(ETH_P_IP);
- return __br_mdb_ip_get(mdb, &br_dst, __br_ip4_hash(mdb, dst));
+ return br_mdb_ip_get(mdb, &br_dst);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -119,23 +128,17 @@ static struct net_bridge_mdb_entry *br_mdb_ip6_get(
ipv6_addr_copy(&br_dst.u.ip6, dst);
br_dst.proto = htons(ETH_P_IPV6);
- return __br_mdb_ip_get(mdb, &br_dst, __br_ip6_hash(mdb, dst));
+ return br_mdb_ip_get(mdb, &br_dst);
}
#endif
-static struct net_bridge_mdb_entry *br_mdb_ip_get(
- struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
-{
- return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
-}
-
struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
struct sk_buff *skb)
{
struct net_bridge_mdb_htable *mdb = br->mdb;
struct br_ip ip;
- if (!mdb || br->multicast_disabled)
+ if (br->multicast_disabled)
return NULL;
if (BR_INPUT_SKB_CB(skb)->igmp)