Re: 2.6.19/2.6.20 BUG in inet_rtm_newaddr()/__inet_insert_ifa()

[Evgeniy Polyakov <johnpol@2ka.mipt.ru>]

On Fri, Mar 09, 2007 at 11:33:33AM +0100, Frank van Maarseveen (frankvm@frankvm.com) wrote:
> Try this:
> 
> ip addr add 172.18.12.99/21 dev dummy0
> ip addr add broadcast 172.18.15.255 dev dummy0

Attached patch fixes the problem.

nlmsg_parse() in rtm_to_ifaddr() sucessfully returns zero, but
subsequent check for prefix len and LOCAL ifa fails, so NULL is returned
instead of negative error value embedded in the pointer which is
expected by error logic in inet_rtm_newaddr().

---

Return negative error value (embedded in the pointer) instead of returning NULL.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index e10794d..98a00d0 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -502,8 +502,10 @@ static struct in_ifaddr *rtm_to_ifaddr(struct nlmsghdr *nlh)
 		goto errout;
 
 	ifm = nlmsg_data(nlh);
-	if (ifm->ifa_prefixlen > 32 || tb[IFA_LOCAL] == NULL)
+	if (ifm->ifa_prefixlen > 32 || tb[IFA_LOCAL] == NULL) {
+		err = -EINVAL;
 		goto errout;
+	}
 
 	dev = __dev_get_by_index(ifm->ifa_index);
 	if (dev == NULL) {

-- 
	Evgeniy Polyakov