From: Alex Williamson <alex.williamson@redhat.com>
To: Diana Craciun <diana.craciun@oss.nxp.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
Cornelia Huck <cohuck@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH 2/2] vfio/fsl-mc: prevent underflow in vfio_fsl_mc_mmap()
Date: Mon, 2 Nov 2020 14:45:38 -0700 [thread overview]
Message-ID: <20201102144538.2871369d@w520.home> (raw)
In-Reply-To: <20201023112947.GF282278@mwanda>
Hi Diana, same for this one. Thanks,
Alex
On Fri, 23 Oct 2020 14:29:47 +0300
Dan Carpenter <dan.carpenter@oracle.com> wrote:
> My static analsysis tool complains that the "index" can be negative.
> There are some checks in do_mmap() which try to prevent underflows but
> I don't know if they are sufficient for this situation. Either way,
> making "index" unsigned is harmless so let's do it just to be safe.
>
> Fixes: 67247289688d ("vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO regions")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> drivers/vfio/fsl-mc/vfio_fsl_mc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> index 21f22e3da11f..f27e25112c40 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> @@ -472,7 +472,7 @@ static int vfio_fsl_mc_mmap(void *device_data, struct vm_area_struct *vma)
> {
> struct vfio_fsl_mc_device *vdev = device_data;
> struct fsl_mc_device *mc_dev = vdev->mc_dev;
> - int index;
> + unsigned int index;
>
> index = vma->vm_pgoff >> (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT);
>
next prev parent reply other threads:[~2020-11-02 21:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-23 11:29 [PATCH 2/2] vfio/fsl-mc: prevent underflow in vfio_fsl_mc_mmap() Dan Carpenter
2020-11-02 21:45 ` Alex Williamson [this message]
2020-11-03 12:03 ` Diana Craciun OSS
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