Commit 7438189b authored by Nicolas Dichtel's avatar Nicolas Dichtel Committed by David S. Miller

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: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e7d481a6
......@@ -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)));
......
......@@ -1695,17 +1695,20 @@ ip6mr_fill_mroute(struct sk_buff *skb, struct mfc6_cache *c, struct rtmsg *rtm)
int ct;
struct rtnexthop *nhp;
struct net *net = mfc6_net(c);
struct net_device *dev = net->ipv6.vif6_table[c->mf6c_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->mf6c_parent > MAXMIFS)
return -ENOENT;
if (MIF_EXISTS(net, c->mf6c_parent))
RTA_PUT(skb, RTA_IIF, 4, &net->ipv6.vif6_table[c->mf6c_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 (MIF_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)));
......
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