Commit b1d80d12 authored by Jason Wang's avatar Jason Wang
Browse files

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: default avatarDaniel Shapira <daniel@twistlock.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
parent 1a326646

hw/net/pcnet.c

+2 −2
Original line number Diff line number Diff line
@@ -988,14 +988,14 @@ 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 */