Re: [Qemu-devel] [PATCH] hw/net: Fix a heap overflow in xlnx.xps-ethernetlite

[Jason Wang]

On 2016年08月09日 10:24, chaojianhu wrote:
> The .receive callback of xlnx.xps-ethernetlite doesn't check the length
> of data before calling memcpy. As a result, the NetClientState object in
> heap will be overflowd. All versions of qemu with　xlnx.xps-ethernetlite
> will be affected.
>
> Reported-by: chaojianhu <address@hidden>

Patch looks correct. But as reported, please add Signed-off-by with your 
name and repost.

Thanks

> ---
>   hw/net/xilinx_ethlite.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/hw/net/xilinx_ethlite.c b/hw/net/xilinx_ethlite.c
> index 54db2b8..6d3eecc 100644
> --- a/hw/net/xilinx_ethlite.c
> +++ b/hw/net/xilinx_ethlite.c
> @@ -197,6 +197,10 @@ static ssize_t eth_rx(NetClientState *nc, const uint8_t 
> *buf, size_t size)
>       }
>   
>       D(qemu_log("%s %zd rxbase=%x\n", __func__, size, rxbase));
> +    if (size > (R_MAX - R_RX_BUF0 - rxbase) * 4 ) {
> +        D(qemu_log("ethlite packet is too big, size=%x\n", size);
> +        return -1;
> +    }
>       memcpy(&s->regs[rxbase + R_RX_BUF0], buf, size);
>   
>       s->regs[rxbase + R_RX_CTRL0] |= CTRL_S;