Re: [PATCH] vduse: prevent uninitialized memory accesses
On 8/27/22 08:54, Dan Carpenter wrote: On Fri, Aug 26, 2022 at 06:16:05PM +0200, Maxime Coquelin wrote: If the VDUSE application provides a smaller config space than the driver expects, the driver may use uninitialized memory from the stack. This patch prevents it by initializing the buffer passed by the driver to store the config value. Signed-off-by: Maxime Coquelin This sounds like it needs a Fixes tag? Yes, I actually did it, but somehow forgot to generate the patch bedore posting. I'll post a v2 soon. Thanks, Maxime regards, dan carpenter ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH] vduse: prevent uninitialized memory accesses
On Sat, Aug 27, 2022 at 12:16 AM Maxime Coquelin
wrote:
>
> If the VDUSE application provides a smaller config space
> than the driver expects, the driver may use uninitialized
> memory from the stack.
>
> This patch prevents it by initializing the buffer passed by
> the driver to store the config value.
>
> Signed-off-by: Maxime Coquelin
Acked-by: Jason Wang
> ---
> drivers/vdpa/vdpa_user/vduse_dev.c | 9 +++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c
> b/drivers/vdpa/vdpa_user/vduse_dev.c
> index 41c0b29739f1..35dceee3ed56 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -673,10 +673,15 @@ static void vduse_vdpa_get_config(struct vdpa_device
> *vdpa, unsigned int offset,
> {
> struct vduse_dev *dev = vdpa_to_vduse(vdpa);
>
> - if (offset > dev->config_size ||
> - len > dev->config_size - offset)
> + /* Initialize the buffer in case of partial copy. */
> + memset(buf, 0, len);
> +
> + if (offset > dev->config_size)
> return;
>
> + if (len > dev->config_size - offset)
> + len = dev->config_size - offset;
> +
> memcpy(buf, dev->config + offset, len);
> }
>
> --
> 2.37.1
>
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Re: [PATCH] vduse: prevent uninitialized memory accesses
On Fri, Aug 26, 2022 at 06:16:05PM +0200, Maxime Coquelin wrote: > If the VDUSE application provides a smaller config space > than the driver expects, the driver may use uninitialized > memory from the stack. > > This patch prevents it by initializing the buffer passed by > the driver to store the config value. > > Signed-off-by: Maxime Coquelin This sounds like it needs a Fixes tag? regards, dan carpenter ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
