Hi Dan,
On Wed, Feb 03, 2021 at 01:10:41PM +0300, Dan Carpenter wrote:
> Hello Andrea Parri (Microsoft),
>
> This is a semi-automatic email about new static checker warnings.
>
> The patch 0ba35fe91ce3: "hv_netvsc: Copy packets sent by Hyper-V out
> of the receive buffer" from Jan 26, 2021, leads to the following
> Smatch complaint:
>
> drivers/net/hyperv/rndis_filter.c:468 rsc_add_data()
> error: we previously assumed 'csum_info' could be null (see line 460)
>
> drivers/net/hyperv/rndis_filter.c
> 459 }
> 460 if (csum_info != NULL) {
> ^^^^^^^^^^^^^^^^^
> "csum_info" can be NULL.
>
> 461 memcpy(&nvchan->rsc.csum_info, csum_info, sizeof(*csum_info));
> 462 nvchan->rsc.ppi_flags |= NVSC_RSC_CSUM_INFO;
> 463 } else {
> 464 nvchan->rsc.ppi_flags &= ~NVSC_RSC_CSUM_INFO;
> 465 }
> 466 nvchan->rsc.pktlen = len;
> 467 if (hash_info != NULL) {
> 468 nvchan->rsc.csum_info = *csum_info;
> ^^^^^^^^^^^
> Unchecked dereference. Plus this has "csum_info" on both sides of the
> assignment so maybe it is a copy and paste error? This is equivalent to
> the "memcpy(&nvchan->rsc.csum_info, csum_info, sizeof(*csum_info));"
> in the ealier if statement but stated as an assignment instead of a
> memcpy().
Right, I did realize about the error and I'm about to send a fix for it.
Thank you for the report,
Andrea
