File CVE-2018-17962-qemuu-pcnet-integer-overflow-leads-to-buffer-overflow.patch of Package xen.10697

References:  bsc#1111011 CVE-2018-17962

In pcnet_receive(), we try to assign size_ to size which converts from
size_t to integer. This will cause troubles when size_ is greater
INT_MAX, this will lead a negative value in size and it can then pass
the check of size < MIN_BUF_SIZE which may lead out of bound access
for both buf and buf1.

Fixing by converting the type of size to size_t.

CC: address@hidden
Reported-by: Daniel Shapira <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Jason Wang <address@hidden>
---
 hw/net/pcnet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/net/pcnet.c
===================================================================
--- xen-4.4.4-testing.orig/tools/qemu-xen-dir-remote/hw/net/pcnet.c
+++ xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/net/pcnet.c
@@ -1026,14 +1026,14 @@ ssize_t pcnet_receive(NetClientState *nc
     uint8_t buf1[60];
     int remaining;
     int crc_err = 0;
-    int size = size_;
+    size_t size = size_;
 
     if (CSR_DRX(s) || CSR_STOP(s) || CSR_SPND(s) || !size ||
         (CSR_LOOP(s) && !s->looptest)) {
         return -1;
     }
 #ifdef PCNET_DEBUG
-    printf("pcnet_receive size=%d\n", size);
+    printf("pcnet_receive size=%zu\n", size);
 #endif
 
     /* if too small buffer, then expand it */