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>
This commit is contained in:
Jason Wang 2018-05-30 13:08:15 +08:00
parent 7da2d99fb9
commit fdc89e90fa

View File

@ -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))