File 0305-pcnet-fix-possible-buffer-overflow.patch of Package qemu.19799

From: Jason Wang <jasowang@redhat.com>
Date: Wed, 30 May 2018 12:11:30 +0800
Subject: pcnet: fix possible buffer overflow

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: qemu-stable@nongnu.org
Reported-by: Daniel Shapira <daniel@twistlock.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit b1d80d12c5f7ff081bb80ab4f4241d4248691192)
[LD: BSC#1111010 CVE-2018-17962]
Signed-off-by: Larry Dewey <ldewey@suse.com>
---
 hw/net/pcnet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
index 3078de8aba88438b332c1751ceec..f201b96b439979f3480408a0c0e6 100644
--- a/hw/net/pcnet.c
+++ b/hw/net/pcnet.c
@@ -1004,14 +1004,14 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
     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 */