ipv6: fix out of bound writes in __ip6_append_data()
[pandora-kernel.git] / net / ipv6 / ip6_output.c
index 91d0711..4ce3e3f 100644 (file)
@@ -144,8 +144,8 @@ static int ip6_finish_output2(struct sk_buff *skb)
                return res;
        }
        rcu_read_unlock();
-       IP6_INC_STATS_BH(dev_net(dst->dev),
-                        ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
+       IP6_INC_STATS(dev_net(dst->dev),
+                     ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
        kfree_skb(skb);
        return -EINVAL;
 }
@@ -562,13 +562,12 @@ static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 {
        u16 offset = sizeof(struct ipv6hdr);
-       struct ipv6_opt_hdr *exthdr =
-                               (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
        unsigned int packet_len = skb->tail - skb->network_header;
        int found_rhdr = 0;
        *nexthdr = &ipv6_hdr(skb)->nexthdr;
 
-       while (offset + 1 <= packet_len) {
+       while (offset <= packet_len) {
+               struct ipv6_opt_hdr *exthdr;
 
                switch (**nexthdr) {
 
@@ -589,38 +588,33 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
                        return offset;
                }
 
-               offset += ipv6_optlen(exthdr);
-               *nexthdr = &exthdr->nexthdr;
+               if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
+                       return -EINVAL;
+
                exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
                                                 offset);
+               offset += ipv6_optlen(exthdr);
+               *nexthdr = &exthdr->nexthdr;
        }
 
-       return offset;
+       return -EINVAL;
 }
 
 void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
 {
-       static atomic_t ipv6_fragmentation_id;
-       int old, new;
+       static u32 ip6_idents_hashrnd __read_mostly;
+       static bool hashrnd_initialized = false;
+       u32 hash, id;
 
-       if (rt && !(rt->dst.flags & DST_NOPEER)) {
-               struct inet_peer *peer;
-
-               if (!rt->rt6i_peer)
-                       rt6_bind_peer(rt, 1);
-               peer = rt->rt6i_peer;
-               if (peer) {
-                       fhdr->identification = htonl(inet_getid(peer, 0));
-                       return;
-               }
+       if (unlikely(!hashrnd_initialized)) {
+               hashrnd_initialized = true;
+               get_random_bytes(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
        }
-       do {
-               old = atomic_read(&ipv6_fragmentation_id);
-               new = old + 1;
-               if (!new)
-                       new = 1;
-       } while (atomic_cmpxchg(&ipv6_fragmentation_id, old, new) != old);
-       fhdr->identification = htonl(new);
+       hash = __ipv6_addr_jhash(&rt->rt6i_dst.addr, ip6_idents_hashrnd);
+       hash = __ipv6_addr_jhash(&rt->rt6i_src.addr, hash);
+
+       id = ip_idents_reserve(hash, 1);
+       fhdr->identification = htonl(id);
 }
 
 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
@@ -631,12 +625,16 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
        struct ipv6hdr *tmp_hdr;
        struct frag_hdr *fh;
        unsigned int mtu, hlen, left, len;
+       int hroom, troom;
        __be32 frag_id = 0;
        int ptr, offset = 0, err=0;
        u8 *prevhdr, nexthdr = 0;
        struct net *net = dev_net(skb_dst(skb)->dev);
 
-       hlen = ip6_find_1stfragopt(skb, &prevhdr);
+       err = ip6_find_1stfragopt(skb, &prevhdr);
+       if (err < 0)
+               goto fail;
+       hlen = err;
        nexthdr = *prevhdr;
 
        mtu = ip6_skb_dst_mtu(skb);
@@ -797,6 +795,8 @@ slow_path:
         */
 
        *prevhdr = NEXTHDR_FRAGMENT;
+       hroom = LL_RESERVED_SPACE(rt->dst.dev);
+       troom = rt->dst.dev->needed_tailroom;
 
        /*
         *      Keep copying data until we run out.
@@ -815,7 +815,8 @@ slow_path:
                 *      Allocate buffer.
                 */
 
-               if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->dst.dev), GFP_ATOMIC)) == NULL) {
+               if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
+                                     hroom + troom, GFP_ATOMIC)) == NULL) {
                        NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
                        IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
                                      IPSTATS_MIB_FRAGFAILS);
@@ -828,7 +829,7 @@ slow_path:
                 */
 
                ip6_copy_metadata(frag, skb);
-               skb_reserve(frag, LL_RESERVED_SPACE(rt->dst.dev));
+               skb_reserve(frag, hroom);
                skb_put(frag, len + hlen + sizeof(struct frag_hdr));
                skb_reset_network_header(frag);
                fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
@@ -1113,9 +1114,8 @@ static inline int ip6_ufo_append_data(struct sock *sk,
                        int getfrag(void *from, char *to, int offset, int len,
                        int odd, struct sk_buff *skb),
                        void *from, int length, int hh_len, int fragheaderlen,
-                       int transhdrlen, int mtu,unsigned int flags,
-                       struct rt6_info *rt)
-
+                       int exthdrlen, int transhdrlen, int mtu,
+                       unsigned int flags, struct rt6_info *rt)
 {
        struct sk_buff *skb;
        int err;
@@ -1140,7 +1140,7 @@ static inline int ip6_ufo_append_data(struct sock *sk,
                skb_put(skb,fragheaderlen + transhdrlen);
 
                /* initialize network header pointer */
-               skb_reset_network_header(skb);
+               skb_set_network_header(skb, exthdrlen);
 
                /* initialize protocol header pointer */
                skb->transport_header = skb->network_header + fragheaderlen;
@@ -1180,21 +1180,19 @@ static void ip6_append_data_mtu(unsigned int *mtu,
                                unsigned int fragheaderlen,
                                struct sk_buff *skb,
                                struct rt6_info *rt,
-                               bool pmtuprobe)
+                               unsigned int orig_mtu)
 {
        if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
                if (skb == NULL) {
                        /* first fragment, reserve header_len */
-                       *mtu = *mtu - rt->dst.header_len;
+                       *mtu = orig_mtu - rt->dst.header_len;
 
                } else {
                        /*
                         * this fragment is not first, the headers
                         * space is regarded as data space.
                         */
-                       *mtu = min(*mtu, pmtuprobe ?
-                                  rt->dst.dev->mtu :
-                                  dst_mtu(rt->dst.path));
+                       *mtu = orig_mtu;
                }
                *maxfraglen = ((*mtu - fragheaderlen) & ~7)
                              + fragheaderlen - sizeof(struct frag_hdr);
@@ -1211,7 +1209,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct inet_cork *cork;
        struct sk_buff *skb, *skb_prev = NULL;
-       unsigned int maxfraglen, fragheaderlen, mtu;
+       unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
        int exthdrlen;
        int dst_exthdrlen;
        int hh_len;
@@ -1296,6 +1294,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
                dst_exthdrlen = 0;
                mtu = cork->fragsize;
        }
+       orig_mtu = mtu;
 
        hh_len = LL_RESERVED_SPACE(rt->dst.dev);
 
@@ -1342,11 +1341,12 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
        skb = skb_peek_tail(&sk->sk_write_queue);
        cork->length += length;
        if (((length > mtu) ||
-            (skb && skb_is_gso(skb))) &&
+            (skb && skb_has_frags(skb))) &&
            (sk->sk_protocol == IPPROTO_UDP) &&
-           (rt->dst.dev->features & NETIF_F_UFO)) {
+           (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len &&
+           (sk->sk_type == SOCK_DGRAM)) {
                err = ip6_ufo_append_data(sk, getfrag, from, length,
-                                         hh_len, fragheaderlen,
+                                         hh_len, fragheaderlen, exthdrlen,
                                          transhdrlen, mtu, flags, rt);
                if (err)
                        goto error;
@@ -1378,8 +1378,7 @@ alloc_new_skb:
                        if (skb == NULL || skb_prev == NULL)
                                ip6_append_data_mtu(&mtu, &maxfraglen,
                                                    fragheaderlen, skb, rt,
-                                                   np->pmtudisc ==
-                                                   IPV6_PMTUDISC_PROBE);
+                                                   orig_mtu);
 
                        skb_prev = skb;
 
@@ -1417,6 +1416,11 @@ alloc_new_skb:
                         */
                        alloclen += sizeof(struct frag_hdr);
 
+                       copy = datalen - transhdrlen - fraggap;
+                       if (copy < 0) {
+                               err = -EINVAL;
+                               goto error;
+                       }
                        if (transhdrlen) {
                                skb = sock_alloc_send_skb(sk,
                                                alloclen + hh_len,
@@ -1468,13 +1472,9 @@ alloc_new_skb:
                                data += fraggap;
                                pskb_trim_unique(skb_prev, maxfraglen);
                        }
-                       copy = datalen - transhdrlen - fraggap;
-
-                       if (copy < 0) {
-                               err = -EINVAL;
-                               kfree_skb(skb);
-                               goto error;
-                       } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
+                       if (copy > 0 &&
+                           getfrag(from, data + transhdrlen, offset,
+                                   copy, fraggap, skb) < 0) {
                                err = -EFAULT;
                                kfree_skb(skb);
                                goto error;
@@ -1649,8 +1649,8 @@ int ip6_push_pending_frames(struct sock *sk)
        if (proto == IPPROTO_ICMPV6) {
                struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 
-               ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type);
-               ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
+               ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
+               ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
        }
 
        err = ip6_local_out(skb);