[IPV6]: Check outgoing interface even if source address is unspecified.

The outgoing interface index (ipi6_ifindex) in IPV6_PKTINFO
ancillary data, is not checked if the source address (ipi6_addr)
is unspecified.  If the ipi6_ifindex is the not-exist interface,
it should be fail.

Based on patch from Shan Wei <shanwei@cn.fujitsu.com> and
Brian Haley <brian.haley@hp.com>.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 22 insertions, 20 deletions

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 94fa6ae77cfe..53e3883f7666 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -509,7 +509,6 @@ int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
 
         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
                 int addr_type;
-                struct net_device *dev = NULL;
 
                 if (!CMSG_OK(msg, cmsg)) {
                         err = -EINVAL;
@@ -522,6 +521,9 @@ int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
                 switch (cmsg->cmsg_type) {
                 case IPV6_PKTINFO:
                 case IPV6_2292PKTINFO:
+                    {
+                        struct net_device *dev = NULL;
+
                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
                                 err = -EINVAL;
                                 goto exit_f;
@@ -535,32 +537,32 @@ int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
                                 fl->oif = src_info->ipi6_ifindex;
                         }
 
-                        addr_type = ipv6_addr_type(&src_info->ipi6_addr);
+                        addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 
-                        if (addr_type == IPV6_ADDR_ANY)
-                                break;
+                        if (fl->oif) {
+                                dev = dev_get_by_index(&init_net, fl->oif);
+                                if (!dev)
+                                        return -ENODEV;
+                        } else if (addr_type & IPV6_ADDR_LINKLOCAL)
+                                return -EINVAL;
 
-                        if (addr_type & IPV6_ADDR_LINKLOCAL) {
-                                if (!src_info->ipi6_ifindex)
-                                        return -EINVAL;
-                                else {
-                                        dev = dev_get_by_index(&init_net, src_info->ipi6_ifindex);
-                                        if (!dev)
-                                                return -ENODEV;
-                                }
-                        }
-                        if (!ipv6_chk_addr(&init_net, &src_info->ipi6_addr,
-                                           dev, 0)) {
-                                if (dev)
-                                        dev_put(dev);
-                                err = -EINVAL;
-                                goto exit_f;
+                        if (addr_type != IPV6_ADDR_ANY) {
+                                int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
+                                if (!ipv6_chk_addr(&init_net, &src_info->ipi6_addr,
+                                                   strict ? dev : NULL, 0))
+                                        err = -EINVAL;
+                                else
+                                        ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
                         }
+
                         if (dev)
                                 dev_put(dev);
 
-                        ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
+                        if (err)
+                                goto exit_f;
+
                         break;
+                    }
 
                 case IPV6_FLOWINFO:
                         if (cmsg->cmsg_len < CMSG_LEN(4)) {