diff mbox

[v4] virtio_blk: Fix an SG_IO regression

Message ID 20171026101015.29855-1-bart.vanassche@wdc.com (mailing list archive)
State New, archived
Headers show

Commit Message

Bart Van Assche Oct. 26, 2017, 10:10 a.m. UTC
Avoid that submitting an SG_IO ioctl triggers a kernel oops that
is preceded by:

usercopy: kernel memory overwrite attempt detected to (null) (<null>) (6 bytes)
kernel BUG at mm/usercopy.c:72!

Reported-by: Dann Frazier <dann.frazier@canonical.com>
Fixes: commit ca18d6f769d2 ("block: Make most scsi_req_init() calls implicit")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Dann Frazier <dann.frazier@canonical.com>
Cc: <stable@vger.kernel.org> # v4.13
---
 drivers/block/virtio_blk.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Christoph Hellwig Oct. 27, 2017, 6:39 a.m. UTC | #1
On Thu, Oct 26, 2017 at 12:10:15PM +0200, Bart Van Assche wrote:
> Avoid that submitting an SG_IO ioctl triggers a kernel oops that
> is preceded by:
> 
> usercopy: kernel memory overwrite attempt detected to (null) (<null>) (6 bytes)
> kernel BUG at mm/usercopy.c:72!
> 
> Reported-by: Dann Frazier <dann.frazier@canonical.com>
> Fixes: commit ca18d6f769d2 ("block: Make most scsi_req_init() calls implicit")
> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Dann Frazier <dann.frazier@canonical.com>
> Cc: <stable@vger.kernel.org> # v4.13
> ---
>  drivers/block/virtio_blk.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 34e17ee799be..e477d4a5181e 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -593,10 +593,20 @@ static int virtblk_map_queues(struct blk_mq_tag_set *set)
>  	return blk_mq_virtio_map_queues(set, vblk->vdev, 0);
>  }
>  
> +static void virtblk_initialize_rq(struct request *req)
> +{
> +	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
> +
> +#ifdef CONFIG_VIRTIO_BLK_SCSI
> +	scsi_req_init(&vbr->sreq);
> +#endif

How about only defininig the initialize_rq method and implementation
if CONFIG_VIRTIO_BLK_SCSI is set?

Else looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Jens Axboe Oct. 27, 2017, 2:24 p.m. UTC | #2
On 10/27/2017 12:39 AM, Christoph Hellwig wrote:
> On Thu, Oct 26, 2017 at 12:10:15PM +0200, Bart Van Assche wrote:
>> Avoid that submitting an SG_IO ioctl triggers a kernel oops that
>> is preceded by:
>>
>> usercopy: kernel memory overwrite attempt detected to (null) (<null>) (6 bytes)
>> kernel BUG at mm/usercopy.c:72!
>>
>> Reported-by: Dann Frazier <dann.frazier@canonical.com>
>> Fixes: commit ca18d6f769d2 ("block: Make most scsi_req_init() calls implicit")
>> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Cc: Dann Frazier <dann.frazier@canonical.com>
>> Cc: <stable@vger.kernel.org> # v4.13
>> ---
>>  drivers/block/virtio_blk.c | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
>> index 34e17ee799be..e477d4a5181e 100644
>> --- a/drivers/block/virtio_blk.c
>> +++ b/drivers/block/virtio_blk.c
>> @@ -593,10 +593,20 @@ static int virtblk_map_queues(struct blk_mq_tag_set *set)
>>  	return blk_mq_virtio_map_queues(set, vblk->vdev, 0);
>>  }
>>  
>> +static void virtblk_initialize_rq(struct request *req)
>> +{
>> +	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
>> +
>> +#ifdef CONFIG_VIRTIO_BLK_SCSI
>> +	scsi_req_init(&vbr->sreq);
>> +#endif
> 
> How about only defininig the initialize_rq method and implementation
> if CONFIG_VIRTIO_BLK_SCSI is set?
> 
> Else looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

I did that while merging it.
Bart Van Assche Oct. 28, 2017, 5:06 p.m. UTC | #3
On Fri, 2017-10-27 at 08:24 -0600, Jens Axboe wrote:
> On 10/27/2017 12:39 AM, Christoph Hellwig wrote:

> > How about only defininig the initialize_rq method and implementation

> > if CONFIG_VIRTIO_BLK_SCSI is set?

> 

> I did that while merging it.


Thanks Jens and Christoph!

Bart.
diff mbox

Patch

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 34e17ee799be..e477d4a5181e 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -593,10 +593,20 @@  static int virtblk_map_queues(struct blk_mq_tag_set *set)
 	return blk_mq_virtio_map_queues(set, vblk->vdev, 0);
 }
 
+static void virtblk_initialize_rq(struct request *req)
+{
+	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
+
+#ifdef CONFIG_VIRTIO_BLK_SCSI
+	scsi_req_init(&vbr->sreq);
+#endif
+}
+
 static const struct blk_mq_ops virtio_mq_ops = {
 	.queue_rq	= virtio_queue_rq,
 	.complete	= virtblk_request_done,
 	.init_request	= virtblk_init_request,
+	.initialize_rq_fn = virtblk_initialize_rq,
 	.map_queues	= virtblk_map_queues,
 };