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().
469 nvchan->rsc.ppi_flags |= NVSC_RSC_HASH_INFO;
470 } else {
regards,
dan carpenter