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* [PATCH] vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter
@ 2013-10-25 18:07 ` Nicholas A. Bellinger
  0 siblings, 0 replies; 6+ messages in thread
From: Nicholas A. Bellinger @ 2013-10-25 18:07 UTC (permalink / raw)
  To: target-devel
  Cc: lf-virt, kvm-devel, linux-scsi, linux-kernel, Stefan Hajnoczi,
	Michael S. Tsirkin, Asias He, Nicholas Bellinger

From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch addresses a long-standing bug where the get_user_pages_fast()
write parameter used for setting the underlying page table entry permission
bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().

However, this parameter is intended to signal WRITEs to pinned userspace
PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.

This bug would manifest itself as random process segmentation faults on
KVM host after repeated vhost starts + stops and/or with lots of vhost
endpoints + LUNs.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Asias He <asias@redhat.com>
Cc: <stable@vger.kernel.org> # 3.6+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/vhost/scsi.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index ce5221f..e663921 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1056,7 +1056,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 		if (data_direction != DMA_NONE) {
 			ret = vhost_scsi_map_iov_to_sgl(cmd,
 					&vq->iov[data_first], data_num,
-					data_direction == DMA_TO_DEVICE);
+					data_direction == DMA_FROM_DEVICE);
 			if (unlikely(ret)) {
 				vq_err(vq, "Failed to map iov to sgl\n");
 				goto err_free;
-- 
1.7.2.5


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH] vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter
@ 2013-10-25 18:07 ` Nicholas A. Bellinger
  0 siblings, 0 replies; 6+ messages in thread
From: Nicholas A. Bellinger @ 2013-10-25 18:07 UTC (permalink / raw)
  To: target-devel
  Cc: kvm-devel, linux-scsi, Michael S. Tsirkin, linux-kernel, lf-virt,
	Stefan Hajnoczi

From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch addresses a long-standing bug where the get_user_pages_fast()
write parameter used for setting the underlying page table entry permission
bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().

However, this parameter is intended to signal WRITEs to pinned userspace
PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.

This bug would manifest itself as random process segmentation faults on
KVM host after repeated vhost starts + stops and/or with lots of vhost
endpoints + LUNs.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Asias He <asias@redhat.com>
Cc: <stable@vger.kernel.org> # 3.6+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/vhost/scsi.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index ce5221f..e663921 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1056,7 +1056,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 		if (data_direction != DMA_NONE) {
 			ret = vhost_scsi_map_iov_to_sgl(cmd,
 					&vq->iov[data_first], data_num,
-					data_direction == DMA_TO_DEVICE);
+					data_direction == DMA_FROM_DEVICE);
 			if (unlikely(ret)) {
 				vq_err(vq, "Failed to map iov to sgl\n");
 				goto err_free;
-- 
1.7.2.5

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH] vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter
  2013-10-25 18:07 ` Nicholas A. Bellinger
@ 2013-10-27 23:48   ` Asias He
  -1 siblings, 0 replies; 6+ messages in thread
From: Asias He @ 2013-10-27 23:48 UTC (permalink / raw)
  To: Nicholas A. Bellinger
  Cc: target-devel, lf-virt, kvm-devel, linux-scsi, linux-kernel,
	Stefan Hajnoczi, Michael S. Tsirkin

On Fri, Oct 25, 2013 at 06:07:16PM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch addresses a long-standing bug where the get_user_pages_fast()
> write parameter used for setting the underlying page table entry permission
> bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
> passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().
> 
> However, this parameter is intended to signal WRITEs to pinned userspace
> PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
> for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.
> 
> This bug would manifest itself as random process segmentation faults on
> KVM host after repeated vhost starts + stops and/or with lots of vhost
> endpoints + LUNs.
> 
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Asias He <asias@redhat.com>
> Cc: <stable@vger.kernel.org> # 3.6+
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Reviewed-by: Asias He <asias@redhat.com>

> ---
>  drivers/vhost/scsi.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index ce5221f..e663921 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1056,7 +1056,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
>  		if (data_direction != DMA_NONE) {
>  			ret = vhost_scsi_map_iov_to_sgl(cmd,
>  					&vq->iov[data_first], data_num,
> -					data_direction == DMA_TO_DEVICE);
> +					data_direction == DMA_FROM_DEVICE);
>  			if (unlikely(ret)) {
>  				vq_err(vq, "Failed to map iov to sgl\n");
>  				goto err_free;
> -- 
> 1.7.2.5
> 

-- 
Asias

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH] vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter
@ 2013-10-27 23:48   ` Asias He
  0 siblings, 0 replies; 6+ messages in thread
From: Asias He @ 2013-10-27 23:48 UTC (permalink / raw)
  To: Nicholas A. Bellinger
  Cc: kvm-devel, linux-scsi, Michael S. Tsirkin, linux-kernel, lf-virt,
	target-devel, Stefan Hajnoczi

On Fri, Oct 25, 2013 at 06:07:16PM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch addresses a long-standing bug where the get_user_pages_fast()
> write parameter used for setting the underlying page table entry permission
> bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
> passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().
> 
> However, this parameter is intended to signal WRITEs to pinned userspace
> PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
> for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.
> 
> This bug would manifest itself as random process segmentation faults on
> KVM host after repeated vhost starts + stops and/or with lots of vhost
> endpoints + LUNs.
> 
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Asias He <asias@redhat.com>
> Cc: <stable@vger.kernel.org> # 3.6+
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Reviewed-by: Asias He <asias@redhat.com>

> ---
>  drivers/vhost/scsi.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index ce5221f..e663921 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1056,7 +1056,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
>  		if (data_direction != DMA_NONE) {
>  			ret = vhost_scsi_map_iov_to_sgl(cmd,
>  					&vq->iov[data_first], data_num,
> -					data_direction == DMA_TO_DEVICE);
> +					data_direction == DMA_FROM_DEVICE);
>  			if (unlikely(ret)) {
>  				vq_err(vq, "Failed to map iov to sgl\n");
>  				goto err_free;
> -- 
> 1.7.2.5
> 

-- 
Asias

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH] vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter
  2013-10-25 18:07 ` Nicholas A. Bellinger
@ 2013-10-28 12:41   ` Michael S. Tsirkin
  -1 siblings, 0 replies; 6+ messages in thread
From: Michael S. Tsirkin @ 2013-10-28 12:41 UTC (permalink / raw)
  To: Nicholas A. Bellinger
  Cc: target-devel, lf-virt, kvm-devel, linux-scsi, linux-kernel,
	Stefan Hajnoczi, Asias He

On Fri, Oct 25, 2013 at 06:07:16PM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch addresses a long-standing bug where the get_user_pages_fast()
> write parameter used for setting the underlying page table entry permission
> bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
> passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().
> 
> However, this parameter is intended to signal WRITEs to pinned userspace
> PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
> for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.
> 
> This bug would manifest itself as random process segmentation faults on
> KVM host after repeated vhost starts + stops and/or with lots of vhost
> endpoints + LUNs.
> 
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Asias He <asias@redhat.com>
> Cc: <stable@vger.kernel.org> # 3.6+
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  drivers/vhost/scsi.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index ce5221f..e663921 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1056,7 +1056,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
>  		if (data_direction != DMA_NONE) {
>  			ret = vhost_scsi_map_iov_to_sgl(cmd,
>  					&vq->iov[data_first], data_num,
> -					data_direction == DMA_TO_DEVICE);
> +					data_direction == DMA_FROM_DEVICE);
>  			if (unlikely(ret)) {
>  				vq_err(vq, "Failed to map iov to sgl\n");
>  				goto err_free;
> -- 
> 1.7.2.5

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH] vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter
@ 2013-10-28 12:41   ` Michael S. Tsirkin
  0 siblings, 0 replies; 6+ messages in thread
From: Michael S. Tsirkin @ 2013-10-28 12:41 UTC (permalink / raw)
  To: Nicholas A. Bellinger
  Cc: kvm-devel, linux-scsi, linux-kernel, lf-virt, target-devel,
	Stefan Hajnoczi

On Fri, Oct 25, 2013 at 06:07:16PM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch addresses a long-standing bug where the get_user_pages_fast()
> write parameter used for setting the underlying page table entry permission
> bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
> passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().
> 
> However, this parameter is intended to signal WRITEs to pinned userspace
> PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
> for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.
> 
> This bug would manifest itself as random process segmentation faults on
> KVM host after repeated vhost starts + stops and/or with lots of vhost
> endpoints + LUNs.
> 
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Asias He <asias@redhat.com>
> Cc: <stable@vger.kernel.org> # 3.6+
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  drivers/vhost/scsi.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index ce5221f..e663921 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1056,7 +1056,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
>  		if (data_direction != DMA_NONE) {
>  			ret = vhost_scsi_map_iov_to_sgl(cmd,
>  					&vq->iov[data_first], data_num,
> -					data_direction == DMA_TO_DEVICE);
> +					data_direction == DMA_FROM_DEVICE);
>  			if (unlikely(ret)) {
>  				vq_err(vq, "Failed to map iov to sgl\n");
>  				goto err_free;
> -- 
> 1.7.2.5

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-10-28 13:38 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-10-25 18:07 [PATCH] vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter Nicholas A. Bellinger
2013-10-25 18:07 ` Nicholas A. Bellinger
2013-10-27 23:48 ` Asias He
2013-10-27 23:48   ` Asias He
2013-10-28 12:41 ` Michael S. Tsirkin
2013-10-28 12:41   ` Michael S. Tsirkin

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