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Maxim Levitsky

2020-Jul-15 09:55 UTC

[PATCH] virtio-blk: check host supplied logical block size

Linux kernel only supports logical block sizes which are power of two,
at least 512 bytes and no more that PAGE_SIZE.

Check this instead of crashing later on.

Note that there is no need to check physical block size since it is
only a hint, and virtio-blk already only supports power of two values.

Bugzilla link: https://bugzilla.redhat.com/show_bug.cgi?id=1664619

Signed-off-by: Maxim Levitsky <mlevitsk at redhat.com>
---
 drivers/block/virtio_blk.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 980df853ee497..36dda31cc4e96 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -681,6 +681,12 @@ static const struct blk_mq_ops virtio_mq_ops = {
 static unsigned int virtblk_queue_depth;
 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
 
+
+static bool virtblk_valid_block_size(unsigned int blksize)
+{
+	return blksize >= 512 && blksize <= PAGE_SIZE &&
is_power_of_2(blksize);
+}
+
 static int virtblk_probe(struct virtio_device *vdev)
 {
 	struct virtio_blk *vblk;
@@ -809,9 +815,16 @@ static int virtblk_probe(struct virtio_device *vdev)
 	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
 				   struct virtio_blk_config, blk_size,
 				   &blk_size);
-	if (!err)
+	if (!err) {
+		if (!virtblk_valid_block_size(blk_size)) {
+			dev_err(&vdev->dev,
+				"%s failure: unsupported logical block size %d\n",
+				__func__, blk_size);
+			err = -EINVAL;
+			goto out_cleanup_queue;
+		}
 		blk_queue_logical_block_size(q, blk_size);
-	else
+	} else
 		blk_size = queue_logical_block_size(q);
 
 	/* Use topology information if available */
@@ -872,6 +885,9 @@ static int virtblk_probe(struct virtio_device *vdev)
 	device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
 	return 0;
 
+out_cleanup_queue:
+	blk_cleanup_queue(vblk->disk->queue);
+	vblk->disk->queue = NULL;
 out_free_tags:
 	blk_mq_free_tag_set(&vblk->tag_set);
 out_put_disk:
-- 
2.26.2

Michael S. Tsirkin

2020-Jul-15 10:06 UTC

head link

[PATCH] virtio-blk: check host supplied logical block size

On Wed, Jul 15, 2020 at 12:55:18PM +0300, Maxim Levitsky
wrote:> Linux kernel only supports logical block sizes which are power of two,
> at least 512 bytes and no more that PAGE_SIZE.
> 
> Check this instead of crashing later on.
> 
> Note that there is no need to check physical block size since it is
> only a hint, and virtio-blk already only supports power of two values.
> 
> Bugzilla link: https://bugzilla.redhat.com/show_bug.cgi?id=1664619
> 
> Signed-off-by: Maxim Levitsky <mlevitsk at redhat.com>
> ---
>  drivers/block/virtio_blk.c | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 980df853ee497..36dda31cc4e96 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -681,6 +681,12 @@ static const struct blk_mq_ops virtio_mq_ops = {
>  static unsigned int virtblk_queue_depth;
>  module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
>  
> +
> +static bool virtblk_valid_block_size(unsigned int blksize)
> +{
> +	return blksize >= 512 && blksize <= PAGE_SIZE &&
is_power_of_2(blksize);
> +}
> +
Is this a blk core assumption? in that case, does not this belong
in blk core?
>  static int virtblk_probe(struct virtio_device *vdev)
>  {
>  	struct virtio_blk *vblk;
> @@ -809,9 +815,16 @@ static int virtblk_probe(struct virtio_device *vdev)
>  	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
>  				   struct virtio_blk_config, blk_size,
>  				   &blk_size);
> -	if (!err)
> +	if (!err) {
> +		if (!virtblk_valid_block_size(blk_size)) {
> +			dev_err(&vdev->dev,
> +				"%s failure: unsupported logical block size %d\n",
> +				__func__, blk_size);
> +			err = -EINVAL;
> +			goto out_cleanup_queue;
> +		}
>  		blk_queue_logical_block_size(q, blk_size);
> -	else
> +	} else
>  		blk_size = queue_logical_block_size(q);
>  
>  	/* Use topology information if available */
OK so if we are doing this pls add {} around  blk_size =
queue_logical_block_size(q);
too.
> @@ -872,6 +885,9 @@ static int virtblk_probe(struct virtio_device *vdev)
>  	device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
>  	return 0;
>  
> +out_cleanup_queue:
> +	blk_cleanup_queue(vblk->disk->queue);
> +	vblk->disk->queue = NULL;
>  out_free_tags:
>  	blk_mq_free_tag_set(&vblk->tag_set);
>  out_put_disk:
> -- 
> 2.26.2

Maxim Levitsky

2020-Jul-15 10:19 UTC

head link

[PATCH] virtio-blk: check host supplied logical block size

On Wed, 2020-07-15 at 06:06 -0400, Michael S. Tsirkin
wrote:> On Wed, Jul 15, 2020 at 12:55:18PM +0300, Maxim Levitsky wrote:
> > Linux kernel only supports logical block sizes which are power of
> > two,
> > at least 512 bytes and no more that PAGE_SIZE.
> > 
> > Check this instead of crashing later on.
> > 
> > Note that there is no need to check physical block size since it is
> > only a hint, and virtio-blk already only supports power of two
> > values.
> > 
> > Bugzilla link: https://bugzilla.redhat.com/show_bug.cgi?id=1664619
> > 
> > Signed-off-by: Maxim Levitsky <mlevitsk at redhat.com>
> > ---
> >  drivers/block/virtio_blk.c | 20 ++++++++++++++++++--
> >  1 file changed, 18 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> > index 980df853ee497..36dda31cc4e96 100644
> > --- a/drivers/block/virtio_blk.c
> > +++ b/drivers/block/virtio_blk.c
> > @@ -681,6 +681,12 @@ static const struct blk_mq_ops virtio_mq_ops >
> {
> >  static unsigned int virtblk_queue_depth;
> >  module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
> >  
> > +
> > +static bool virtblk_valid_block_size(unsigned int blksize)
> > +{
> > +	return blksize >= 512 && blksize <= PAGE_SIZE
&&
> > is_power_of_2(blksize);
> > +}
> > +
> 
> Is this a blk core assumption? in that case, does not this belong
> in blk core?
It is a blk core assumption. 
I had checked other drivers and these that have variable block size all
check this manually like that.

I don't mind fixing all of them but I am a bit afraid to create
too much mess.
> 
> >  static int virtblk_probe(struct virtio_device *vdev)
> >  {
> >  	struct virtio_blk *vblk;
> > @@ -809,9 +815,16 @@ static int virtblk_probe(struct virtio_device
> > *vdev)
> >  	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
> >  				   struct virtio_blk_config, blk_size,
> >  				   &blk_size);
> > -	if (!err)
> > +	if (!err) {
> > +		if (!virtblk_valid_block_size(blk_size)) {
> > +			dev_err(&vdev->dev,
> > +				"%s failure: unsupported logical block
> > size %d\n",
> > +				__func__, blk_size);
> > +			err = -EINVAL;
> > +			goto out_cleanup_queue;
> > +		}
> >  		blk_queue_logical_block_size(q, blk_size);
> > -	else
> > +	} else
> >  		blk_size = queue_logical_block_size(q);
> >  
> >  	/* Use topology information if available */
> 
> OK so if we are doing this pls add {} around  blk_size >
queue_logical_block_size(q);
> too.Will do.
> 
> > @@ -872,6 +885,9 @@ static int virtblk_probe(struct virtio_device
> > *vdev)
> >  	device_add_disk(&vdev->dev, vblk->disk,
virtblk_attr_groups);
> >  	return 0;
> >  
> > +out_cleanup_queue:
> > +	blk_cleanup_queue(vblk->disk->queue);
> > +	vblk->disk->queue = NULL;
> >  out_free_tags:
> >  	blk_mq_free_tag_set(&vblk->tag_set);
> >  out_put_disk:
> > -- 
> > 2.26.2

Best regards,
	Maxim Levitsky

Ming Lei

2020-Jul-15 10:33 UTC

head link

[PATCH] virtio-blk: check host supplied logical block size

On Wed, Jul 15, 2020 at 5:55 PM Maxim Levitsky <mlevitsk at redhat.com>
wrote:>
> Linux kernel only supports logical block sizes which are power of two,
> at least 512 bytes and no more that PAGE_SIZE.
>
> Check this instead of crashing later on.
>
> Note that there is no need to check physical block size since it is
> only a hint, and virtio-blk already only supports power of two values.
>
> Bugzilla link: https://bugzilla.redhat.com/show_bug.cgi?id=1664619
>
> Signed-off-by: Maxim Levitsky <mlevitsk at redhat.com>
> ---
>  drivers/block/virtio_blk.c | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 980df853ee497..36dda31cc4e96 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -681,6 +681,12 @@ static const struct blk_mq_ops virtio_mq_ops = {
>  static unsigned int virtblk_queue_depth;
>  module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
>
> +
> +static bool virtblk_valid_block_size(unsigned int blksize)
> +{
> +       return blksize >= 512 && blksize <= PAGE_SIZE
&& is_power_of_2(blksize);
> +}
> +
>  static int virtblk_probe(struct virtio_device *vdev)
>  {
>         struct virtio_blk *vblk;
> @@ -809,9 +815,16 @@ static int virtblk_probe(struct virtio_device *vdev)
>         err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
>                                    struct virtio_blk_config, blk_size,
>                                    &blk_size);
> -       if (!err)
> +       if (!err) {
> +               if (!virtblk_valid_block_size(blk_size)) {
> +                       dev_err(&vdev->dev,
> +                               "%s failure: unsupported logical block
size %d\n",
> +                               __func__, blk_size);
> +                       err = -EINVAL;
> +                       goto out_cleanup_queue;
> +               }
>                 blk_queue_logical_block_size(q, blk_size);
> -       else
> +       } else
>                 blk_size = queue_logical_block_size(q);
>
>         /* Use topology information if available */
> @@ -872,6 +885,9 @@ static int virtblk_probe(struct virtio_device *vdev)
>         device_add_disk(&vdev->dev, vblk->disk,
virtblk_attr_groups);
>         return 0;
>
> +out_cleanup_queue:
> +       blk_cleanup_queue(vblk->disk->queue);
> +       vblk->disk->queue = NULL;
>  out_free_tags:
>         blk_mq_free_tag_set(&vblk->tag_set);
>  out_put_disk:
> --
> 2.26.2
>
> _______________________________________________
> Virtualization mailing list
> Virtualization at lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Looks fine,

Reviewed-by: Ming Lei <ming.lei at redhat.com>

-- 
Ming Lei

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