Re: [Qemu-devel] [PATCH] ps2: check PS2Queue wptr pointer in post_load routine

[Gonglei (Arei)]

> -----Original Message-----
> From: liujunjie (A)
> Sent: Thursday, June 07, 2018 4:03 PM
> To: address@hidden; address@hidden
> Cc: Gonglei (Arei) <address@hidden>; wangxin (U)
> <address@hidden>; Huangweidong (C)
> <address@hidden>; fangying <address@hidden>;
> address@hidden; liujunjie (A) <address@hidden>
> Subject: [PATCH] ps2: check PS2Queue wptr pointer in post_load routine
> 
> In commit 802cbcb7300, most issues have been fixed when qemu guest
> migration. But the queue size still need to check whether is equal to
> PS2_QUEUE_SIZE. If yes, the wptr should set as 0. Or, wptr would larger
> than PS2_QUEUE_SIZE and never come back when ps2_queue_noirq is called.
> This could lead to OOB access, add check to avoid it.
> 
> Signed-off-by: liujunjie <address@hidden>
> ---
>  hw/input/ps2.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/input/ps2.c b/hw/input/ps2.c
> index eeec618..fdfcadf 100644
> --- a/hw/input/ps2.c
> +++ b/hw/input/ps2.c
> @@ -927,7 +927,7 @@ static void ps2_common_post_load(PS2State *s)
> 
>      /* reset rptr/wptr/count */
>      q->rptr = 0;
> -    q->wptr = size;
> +    q->wptr = (size == PS2_QUEUE_SIZE) ? 0 : size;
>      q->count = size;
>      s->update_irq(s->update_arg, q->count != 0);
>  }
> --

Reviewed-by: Gonglei <address@hidden>