Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:

 1) Null termination fix in dns_resolver got the pointer dereferncing
    wrong, fix from Ben Hutchings.

 2) ip_options_compile() has a benign but real buffer overflow when
    parsing options.  From Eric Dumazet.

 3) Table updates can crash in netfilter's nftables if none of the state
    flags indicate an actual change, from Pablo Neira Ayuso.

 4) Fix race in nf_tables dumping, also from Pablo.

 5) GRE-GRO support broke the forwarding path because the segmentation
    state was not fully initialized in these paths, from Jerry Chu.

 6) sunvnet driver leaks objects and potentially crashes on module
    unload, from Sowmini Varadhan.

 7) We can accidently generate the same handle for several u32
    classifier filters, fix from Cong Wang.

 8) Several edge case bug fixes in fragment handling in xen-netback,
    from Zoltan Kiss.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (21 commits)
  ipv4: fix buffer overflow in ip_options_compile()
  batman-adv: fix TT VLAN inconsistency on VLAN re-add
  batman-adv: drop QinQ claim frames in bridge loop avoidance
  dns_resolver: Null-terminate the right string
  xen-netback: Fix pointer incrementation to avoid incorrect logging
  xen-netback: Fix releasing header slot on error path
  xen-netback: Fix releasing frag_list skbs in error path
  xen-netback: Fix handling frag_list on grant op error path
  net_sched: avoid generating same handle for u32 filters
  net: huawei_cdc_ncm: add "subclass 3" devices
  net: qmi_wwan: add two Sierra Wireless/Netgear devices
  wan/x25_asy: integer overflow in x25_asy_change_mtu()
  net: ppp: fix creating PPP pass and active filters
  net/mlx4_en: cq->irq_desc wasn't set in legacy EQ's
  sunvnet: clean up objects created in vnet_new() on vnet_exit()
  r8169: Enable RX_MULTI_EN for RTL_GIGA_MAC_VER_40
  net-gre-gro: Fix a bug that breaks the forwarding path
  netfilter: nf_tables: 64bit stats need some extra synchronization
  netfilter: nf_tables: set NLM_F_DUMP_INTR if netlink dumping is stale
  netfilter: nf_tables: safe RCU iteration on list when dumping
  ...

1 files changed, 63 insertions, 23 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 1844a47636b6..c65b636bcab9 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1030,14 +1030,21 @@ static int xenvif_tx_check_gop(struct xenvif_queue *queue,
 {
         struct gnttab_map_grant_ref *gop_map = *gopp_map;
         u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
+        /* This always points to the shinfo of the skb being checked, which
+         * could be either the first or the one on the frag_list
+         */
         struct skb_shared_info *shinfo = skb_shinfo(skb);
+        /* If this is non-NULL, we are currently checking the frag_list skb, and
+         * this points to the shinfo of the first one
+         */
+        struct skb_shared_info *first_shinfo = NULL;
         int nr_frags = shinfo->nr_frags;
+        const bool sharedslot = nr_frags &&
+                                frag_get_pending_idx(&shinfo->frags[0]) == pending_idx;
         int i, err;
-        struct sk_buff *first_skb = NULL;
 
         /* Check status of header. */
         err = (*gopp_copy)->status;
-        (*gopp_copy)++;
         if (unlikely(err)) {
                 if (net_ratelimit())
                         netdev_dbg(queue->vif->dev,
@@ -1045,8 +1052,12 @@ static int xenvif_tx_check_gop(struct xenvif_queue *queue,
                                    (*gopp_copy)->status,
                                    pending_idx,
                                    (*gopp_copy)->source.u.ref);
-                xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
+                /* The first frag might still have this slot mapped */
+                if (!sharedslot)
+                        xenvif_idx_release(queue, pending_idx,
+                                           XEN_NETIF_RSP_ERROR);
         }
+        (*gopp_copy)++;
 
 check_frags:
         for (i = 0; i < nr_frags; i++, gop_map++) {
@@ -1062,8 +1073,19 @@ check_frags:
                                                 pending_idx,
                                                 gop_map->handle);
                         /* Had a previous error? Invalidate this fragment. */
-                        if (unlikely(err))
+                        if (unlikely(err)) {
                                 xenvif_idx_unmap(queue, pending_idx);
+                                /* If the mapping of the first frag was OK, but
+                                 * the header's copy failed, and they are
+                                 * sharing a slot, send an error
+                                 */
+                                if (i == 0 && sharedslot)
+                                        xenvif_idx_release(queue, pending_idx,
+                                                           XEN_NETIF_RSP_ERROR);
+                                else
+                                        xenvif_idx_release(queue, pending_idx,
+                                                           XEN_NETIF_RSP_OKAY);
+                        }
                         continue;
                 }
 
@@ -1075,42 +1097,53 @@ check_frags:
                                    gop_map->status,
                                    pending_idx,
                                    gop_map->ref);
+
                 xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
 
                 /* Not the first error? Preceding frags already invalidated. */
                 if (err)
                         continue;
-                /* First error: invalidate preceding fragments. */
+
+                /* First error: if the header haven't shared a slot with the
+                 * first frag, release it as well.
+                 */
+                if (!sharedslot)
+                        xenvif_idx_release(queue,
+                                           XENVIF_TX_CB(skb)->pending_idx,
+                                           XEN_NETIF_RSP_OKAY);
+
+                /* Invalidate preceding fragments of this skb. */
                 for (j = 0; j < i; j++) {
                         pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
                         xenvif_idx_unmap(queue, pending_idx);
+                        xenvif_idx_release(queue, pending_idx,
+                                           XEN_NETIF_RSP_OKAY);
+                }
+
+                /* And if we found the error while checking the frag_list, unmap
+                 * the first skb's frags
+                 */
+                if (first_shinfo) {
+                        for (j = 0; j < first_shinfo->nr_frags; j++) {
+                                pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
+                                xenvif_idx_unmap(queue, pending_idx);
+                                xenvif_idx_release(queue, pending_idx,
+                                                   XEN_NETIF_RSP_OKAY);
+                        }
                 }
 
                 /* Remember the error: invalidate all subsequent fragments. */
                 err = newerr;
         }
 
-        if (skb_has_frag_list(skb)) {
-                first_skb = skb;
-                skb = shinfo->frag_list;
-                shinfo = skb_shinfo(skb);
+        if (skb_has_frag_list(skb) && !first_shinfo) {
+                first_shinfo = skb_shinfo(skb);
+                shinfo = skb_shinfo(skb_shinfo(skb)->frag_list);
                 nr_frags = shinfo->nr_frags;
 
                 goto check_frags;
         }
 
-        /* There was a mapping error in the frag_list skb. We have to unmap
-         * the first skb's frags
-         */
-        if (first_skb && err) {
-                int j;
-                shinfo = skb_shinfo(first_skb);
-                for (j = 0; j < shinfo->nr_frags; j++) {
-                        pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
-                        xenvif_idx_unmap(queue, pending_idx);
-                }
-        }
-
         *gopp_map = gop_map;
         return err;
 }
@@ -1518,7 +1551,16 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
 
                 /* Check the remap error code. */
                 if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
+                        /* If there was an error, xenvif_tx_check_gop is
+                         * expected to release all the frags which were mapped,
+                         * so kfree_skb shouldn't do it again
+                         */
                         skb_shinfo(skb)->nr_frags = 0;
+                        if (skb_has_frag_list(skb)) {
+                                struct sk_buff *nskb =
+                                                skb_shinfo(skb)->frag_list;
+                                skb_shinfo(nskb)->nr_frags = 0;
+                        }
                         kfree_skb(skb);
                         continue;
                 }
@@ -1822,8 +1864,6 @@ void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
                            tx_unmap_op.status);
                 BUG();
         }
-
-        xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_OKAY);
 }
 
 static inline int rx_work_todo(struct xenvif_queue *queue)