From: Jason Wang <jasowang@redhat.com>

Date: Wed, 30 May 2018 13:08:15 +0800

Subject: [PATCH] ne2000: fix possible out of bound access in ne2000_receive

In ne2000_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 of

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 fdc89e90fac40c5ca2686733df17b6423fb8d8fb)

---

 hw/net/ne2000.c | 4 ++--

 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c

index 07d79e317f..869518ee06 100644

--- a/hw/net/ne2000.c

+++ b/hw/net/ne2000.c

@@ -174,7 +174,7 @@ static int ne2000_buffer_full(NE2000State *s)

 ssize_t ne2000_receive(NetClientState *nc, const uint8_t *buf, size_t size_)

 {

     NE2000State *s = qemu_get_nic_opaque(nc);

-    int size = size_;

+    size_t size = size_;

     uint8_t *p;

     unsigned int total_len, next, avail, len, index, mcast_idx;

     uint8_t buf1[60];

@@ -182,7 +182,7 @@ ssize_t ne2000_receive(NetClientState *nc, const uint8_t *buf, size_t size_)

         { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

 #if defined(DEBUG_NE2000)

-    printf("NE2000: received len=%d\n", size);

+    printf("NE2000: received len=%zu\n", size);

 #endif

     if (s->cmd & E8390_STOP || ne2000_buffer_full(s))