net/appletalk: fix minor pointer leak to userspace in SIOCFINDIPDDPRT

Fields ->dev and ->next of struct ipddp_route may be copied to
userspace on the SIOCFINDIPDDPRT ioctl. This is only accessible
to CAP_NET_ADMIN though. Let's manually copy the relevant fields
instead of using memcpy().

BugLink: http://blog.infosectcbr.com.au/2018/09/linux-kernel-infoleaks.html
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Willy Tarreau 2018-09-12 07:36:35 +02:00 committed by David S. Miller
parent 018349d70f
commit 9824dfae57
1 changed files with 6 additions and 2 deletions

View File

@ -283,8 +283,12 @@ static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
case SIOCFINDIPDDPRT:
spin_lock_bh(&ipddp_route_lock);
rp = __ipddp_find_route(&rcp);
if (rp)
memcpy(&rcp2, rp, sizeof(rcp2));
if (rp) {
memset(&rcp2, 0, sizeof(rcp2));
rcp2.ip = rp->ip;
rcp2.at = rp->at;
rcp2.flags = rp->flags;
}
spin_unlock_bh(&ipddp_route_lock);
if (rp) {