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Re: [PATCH] ipmi:smbus: Add a check around a memcpy
From: |
Michael S. Tsirkin |
Subject: |
Re: [PATCH] ipmi:smbus: Add a check around a memcpy |
Date: |
Mon, 1 Aug 2022 02:15:24 -0400 |
On Sun, Jul 31, 2022 at 06:02:46PM -0500, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
>
> In one case:
>
> memcpy(sid->inmsg + sid->inlen, buf, len);
>
> if len == 0 then sid->inmsg + sig->inlen can point to one past the inmsg
> array if the array is full. We have to allow len == 0 due to some
> vagueness in the spec, but we don't have to call memcpy.
>
> Found by Coverity. This is not a problem in practice, but the results
> are technically (maybe) undefined. So make Coverity happy.
>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> hw/ipmi/smbus_ipmi.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> I think this should do it.
>
> diff --git a/hw/ipmi/smbus_ipmi.c b/hw/ipmi/smbus_ipmi.c
> index 9ef9112dd5..d0991ab7f9 100644
> --- a/hw/ipmi/smbus_ipmi.c
> +++ b/hw/ipmi/smbus_ipmi.c
> @@ -281,7 +281,9 @@ static int ipmi_write_data(SMBusDevice *dev, uint8_t
> *buf, uint8_t len)
> */
> send = true;
> }
> - memcpy(sid->inmsg + sid->inlen, buf, len);
> + if (len > 0) {
> + memcpy(sid->inmsg + sid->inlen, buf, len);
> + }
> sid->inlen += len;
> break;
> }
> --
> 2.25.1
- Re: [PATCH] ipmi:smbus: Add a check around a memcpy,
Michael S. Tsirkin <=