Re: [PATCH-for-6.0?] mptsas: remove unused MPTSASState.pending (CVE-2021-3392)

[Philippe Mathieu-Daudé]

On 4/16/21 12:22 PM, Michael Tokarev wrote:
> During previous attempt to fix CVE-2021-3392 it was discovered
> that MPTSASState.pending is actually not used. So instead of
> fixing the prob, just remove the offending code entirely

What problem?

> 
> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
> Cc: Prasad J Pandit <pjp@fedoraproject.org>
> Cc: qemu-stable@nongnu.org
> ---
>  hw/scsi/mptsas.c | 4 ----
>  hw/scsi/mptsas.h | 1 -
>  2 files changed, 5 deletions(-)
> 
> diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
> index 7416e78706..5abbc742aa 100644
> --- a/hw/scsi/mptsas.c
> +++ b/hw/scsi/mptsas.c
> @@ -257,7 +257,6 @@ static void mptsas_free_request(MPTSASRequest *req)
>          req->sreq->hba_private = NULL;
>          scsi_req_unref(req->sreq);
>          req->sreq = NULL;
> -        QTAILQ_REMOVE(&s->pending, req, next);
>      }
>      qemu_sglist_destroy(&req->qsg);
>      g_free(req);
> @@ -303,7 +302,6 @@ static int mptsas_process_scsi_io_request(MPTSASState *s,
>      }
>  
>      req = g_new0(MPTSASRequest, 1);
> -    QTAILQ_INSERT_TAIL(&s->pending, req, next);
>      req->scsi_io = *scsi_io;
>      req->dev = s;
>  
> @@ -1319,8 +1317,6 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error 
> **errp)
>  
>      s->request_bh = qemu_bh_new(mptsas_fetch_requests, s);
>  
> -    QTAILQ_INIT(&s->pending);
> -
>      scsi_bus_new(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info, 
> NULL);
>  }
>  
> diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h
> index b85ac1a5fc..c046497db7 100644
> --- a/hw/scsi/mptsas.h
> +++ b/hw/scsi/mptsas.h
> @@ -79,7 +79,6 @@ struct MPTSASState {
>      uint16_t reply_frame_size;
>  
>      SCSIBus bus;
> -    QTAILQ_HEAD(, MPTSASRequest) pending;
>  };
>  
>  void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req);
>