diff options
| author | Nicolas Dichtel <nicolas.dichtel@dev.6wind.com> | 2010-03-25 23:45:35 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-03-27 08:33:21 -0700 |
| commit | 7438189baa0a2fe30084bdc97e3d540ebc5444f3 (patch) | |
| tree | 6627b63b785df9175e04a0ce1b49d5eea8ea0777 /net/ipv4/ipmr.c | |
| parent | e7d481a6f3c13041446b7bb8f98ab861460076a3 (diff) | |
net: ipmr/ip6mr: prevent out-of-bounds vif_table access
When cache is unresolved, c->mf[6]c_parent is set to 65535 and
minvif, maxvif are not initialized, hence we must avoid to
parse IIF and OIF.
A second problem can happen when the user dumps a cache entry
where a VIF, that was referenced at creation time, has been
removed.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ipmr.c')
| -rw-r--r-- | net/ipv4/ipmr.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 0b9d03c54dc3..d0a6092a67be 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1616,17 +1616,20 @@ ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm) int ct; struct rtnexthop *nhp; struct net *net = mfc_net(c); - struct net_device *dev = net->ipv4.vif_table[c->mfc_parent].dev; u8 *b = skb_tail_pointer(skb); struct rtattr *mp_head; - if (dev) - RTA_PUT(skb, RTA_IIF, 4, &dev->ifindex); + /* If cache is unresolved, don't try to parse IIF and OIF */ + if (c->mfc_parent > MAXVIFS) + return -ENOENT; + + if (VIF_EXISTS(net, c->mfc_parent)) + RTA_PUT(skb, RTA_IIF, 4, &net->ipv4.vif_table[c->mfc_parent].dev->ifindex); mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0)); for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) { - if (c->mfc_un.res.ttls[ct] < 255) { + if (VIF_EXISTS(net, ct) && c->mfc_un.res.ttls[ct] < 255) { if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4)) goto rtattr_failure; nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp))); |