Merge remote-tracking branch 'remotes/stefanha/tags/net-pull-request' into staging

This net pull request contains security fixes for qemu.git/master.  The patches
should also be applied to stable trees.

The ne2000 NIC model has QEMU memory corruption issue.  Both ne2000 and e1000
have an infinite loop.

Please see the patches for CVE numbers and details on the bugs.

# gpg: Signature made Tue 15 Sep 2015 13:02:21 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/net-pull-request:
  net: avoid infinite loop when receiving packets(CVE-2015-5278)
  net: add checks to validate ring buffer pointers(CVE-2015-5279)
  e1000: Avoid infinite loop in processing transmit descriptor (CVE-2015-6815)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 18 insertions, 6 deletions

diff --git a/hw/net/e1000.c b/hw/net/e1000.c
index 5c6bcd0..09c9e9d 100644
--- a/hw/net/e1000.c
+++ b/hw/net/e1000.c
@@ -740,7 +740,8 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp)
                 memmove(tp->data, tp->header, tp->hdr_len);
                 tp->size = tp->hdr_len;
             }
-        } while (split_size -= bytes);
+            split_size -= bytes;
+        } while (bytes && split_size);
     } else if (!tp->tse && tp->cptse) {
         // context descriptor TSE is not set, while data descriptor TSE is set
         DBGOUT(TXERR, "TCP segmentation error\n");
diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
index 53c704a..010f9ef 100644
--- a/hw/net/ne2000.c
+++ b/hw/net/ne2000.c
@@ -221,6 +221,9 @@ ssize_t ne2000_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
     }
 
     index = s->curpag << 8;
+    if (index >= NE2000_PMEM_END) {
+        index = s->start;
+    }
     /* 4 bytes for header */
     total_len = size + 4;
     /* address for next packet (4 bytes for CRC) */
@@ -244,7 +247,7 @@ ssize_t ne2000_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
         if (index <= s->stop)
             avail = s->stop - index;
         else
-            avail = 0;
+            break;
         len = size;
         if (len > avail)
             len = avail;
@@ -306,13 +309,19 @@ static void ne2000_ioport_write(void *opaque, uint32_t addr, uint32_t val)
         offset = addr | (page << 4);
         switch(offset) {
         case EN0_STARTPG:
-            s->start = val << 8;
+            if (val << 8 <= NE2000_PMEM_END) {
+                s->start = val << 8;
+            }
             break;
         case EN0_STOPPG:
-            s->stop = val << 8;
+            if (val << 8 <= NE2000_PMEM_END) {
+                s->stop = val << 8;
+            }
             break;
         case EN0_BOUNDARY:
-            s->boundary = val;
+            if (val << 8 < NE2000_PMEM_END) {
+                s->boundary = val;
+            }
             break;
         case EN0_IMR:
             s->imr = val;
@@ -353,7 +362,9 @@ static void ne2000_ioport_write(void *opaque, uint32_t addr, uint32_t val)
             s->phys[offset - EN1_PHYS] = val;
             break;
         case EN1_CURPAG:
-            s->curpag = val;
+            if (val << 8 < NE2000_PMEM_END) {
+                s->curpag = val;
+            }
             break;
         case EN1_MULT ... EN1_MULT + 7:
             s->mult[offset - EN1_MULT] = val;