Commit 639739b5 authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller

ipv6: fix null pointer dereference in __ip6addrlbl_add

Commit b67bfe0d ("hlist: drop
the node parameter from iterators") changed the behavior of
hlist_for_each_entry_safe to leave the p argument NULL.

Fix this up by tracking the last argument.
Reported-by: default avatarMichele Baldessari <michele@acksyn.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Tested-by: default avatarMichele Baldessari <michele@acksyn.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a8e9fd0f
......@@ -251,38 +251,36 @@ static struct ip6addrlbl_entry *ip6addrlbl_alloc(struct net *net,
/* add a label */
static int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
{
struct hlist_node *n;
struct ip6addrlbl_entry *last = NULL, *p = NULL;
int ret = 0;
ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
__func__,
newp, replace);
ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n", __func__, newp,
replace);
if (hlist_empty(&ip6addrlbl_table.head)) {
hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
} else {
struct hlist_node *n;
struct ip6addrlbl_entry *p = NULL;
hlist_for_each_entry_safe(p, n,
&ip6addrlbl_table.head, list) {
if (p->prefixlen == newp->prefixlen &&
net_eq(ip6addrlbl_net(p), ip6addrlbl_net(newp)) &&
p->ifindex == newp->ifindex &&
ipv6_addr_equal(&p->prefix, &newp->prefix)) {
if (!replace) {
ret = -EEXIST;
goto out;
}
hlist_replace_rcu(&p->list, &newp->list);
ip6addrlbl_put(p);
goto out;
} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
(p->prefixlen < newp->prefixlen)) {
hlist_add_before_rcu(&newp->list, &p->list);
hlist_for_each_entry_safe(p, n, &ip6addrlbl_table.head, list) {
if (p->prefixlen == newp->prefixlen &&
net_eq(ip6addrlbl_net(p), ip6addrlbl_net(newp)) &&
p->ifindex == newp->ifindex &&
ipv6_addr_equal(&p->prefix, &newp->prefix)) {
if (!replace) {
ret = -EEXIST;
goto out;
}
hlist_replace_rcu(&p->list, &newp->list);
ip6addrlbl_put(p);
goto out;
} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
(p->prefixlen < newp->prefixlen)) {
hlist_add_before_rcu(&newp->list, &p->list);
goto out;
}
hlist_add_after_rcu(&p->list, &newp->list);
last = p;
}
if (last)
hlist_add_after_rcu(&last->list, &newp->list);
else
hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
out:
if (!ret)
ip6addrlbl_table.seq++;
......
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