There is no check about the return value of kmalloc in
virtscsi_rescan_hotunplug. Add the check to avoid use
of null pointer 'inq_result' in case of the failure
of kmalloc.
Signed-off-by: Zheng Wang <[email protected]>
---
v2:
- add kfree to avoid memory leak
---
drivers/scsi/virtio_scsi.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index d07d24c06b54..a66d8815d738 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -330,7 +330,7 @@ static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
scsi_device_put(sdev);
}
-static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
+static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
{
struct scsi_device *sdev;
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
@@ -338,6 +338,11 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
int result, inquiry_len, inq_result_len = 256;
char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
+ if (!inq_result) {
+ kfree(inq_result);
+ return -ENOMEM;
+ }
+
shost_for_each_device(sdev, shost) {
inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
@@ -366,6 +371,7 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
}
kfree(inq_result);
+ return 0;
}
static void virtscsi_handle_event(struct work_struct *work)
@@ -374,12 +380,15 @@ static void virtscsi_handle_event(struct work_struct *work)
container_of(work, struct virtio_scsi_event_node, work);
struct virtio_scsi *vscsi = event_node->vscsi;
struct virtio_scsi_event *event = &event_node->event;
+ int ret = 0;
if (event->event &
cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
event->event &= ~cpu_to_virtio32(vscsi->vdev,
VIRTIO_SCSI_T_EVENTS_MISSED);
- virtscsi_rescan_hotunplug(vscsi);
+ ret = virtscsi_rescan_hotunplug(vscsi);
+ if (ret)
+ return;
scsi_scan_host(virtio_scsi_host(vscsi->vdev));
}
--
2.25.1
After writing the patch, I found there is an old patch about this issue.
The link is : https://lore.kernel.org/all/[email protected]/
Best regards,
Zheng Wang
Zheng Wang <[email protected]> 于2023年2月2日周四 14:42写道：
>
> There is no check about the return value of kmalloc in
> virtscsi_rescan_hotunplug. Add the check to avoid use
> of null pointer 'inq_result' in case of the failure
> of kmalloc.
>
> Signed-off-by: Zheng Wang <[email protected]>
> ---
> v2:
> - add kfree to avoid memory leak
> ---
> drivers/scsi/virtio_scsi.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> index d07d24c06b54..a66d8815d738 100644
> --- a/drivers/scsi/virtio_scsi.c
> +++ b/drivers/scsi/virtio_scsi.c
> @@ -330,7 +330,7 @@ static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
> scsi_device_put(sdev);
> }
>
> -static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> +static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> {
> struct scsi_device *sdev;
> struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
> @@ -338,6 +338,11 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> int result, inquiry_len, inq_result_len = 256;
> char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
>
> + if (!inq_result) {
> + kfree(inq_result);
> + return -ENOMEM;
> + }
> +
> shost_for_each_device(sdev, shost) {
> inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
>
> @@ -366,6 +371,7 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> }
>
> kfree(inq_result);
> + return 0;
> }
>
> static void virtscsi_handle_event(struct work_struct *work)
> @@ -374,12 +380,15 @@ static void virtscsi_handle_event(struct work_struct *work)
> container_of(work, struct virtio_scsi_event_node, work);
> struct virtio_scsi *vscsi = event_node->vscsi;
> struct virtio_scsi_event *event = &event_node->event;
> + int ret = 0;
>
> if (event->event &
> cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
> event->event &= ~cpu_to_virtio32(vscsi->vdev,
> VIRTIO_SCSI_T_EVENTS_MISSED);
> - virtscsi_rescan_hotunplug(vscsi);
> + ret = virtscsi_rescan_hotunplug(vscsi);
> + if (ret)
> + return;
> scsi_scan_host(virtio_scsi_host(vscsi->vdev));
> }
>
> --
> 2.25.1
>
On Thu, Feb 02, 2023 at 02:41:24PM +0800, Zheng Wang wrote:
> There is no check about the return value of kmalloc in
> virtscsi_rescan_hotunplug. Add the check to avoid use
> of null pointer 'inq_result' in case of the failure
> of kmalloc.
>
> Signed-off-by: Zheng Wang <[email protected]>
> ---
I fixed a typo in subject and tweaked the patch a bit
> v2:
> - add kfree to avoid memory leak
> ---
> drivers/scsi/virtio_scsi.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> index d07d24c06b54..a66d8815d738 100644
> --- a/drivers/scsi/virtio_scsi.c
> +++ b/drivers/scsi/virtio_scsi.c
> @@ -330,7 +330,7 @@ static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
> scsi_device_put(sdev);
> }
>
> -static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> +static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> {
> struct scsi_device *sdev;
> struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
> @@ -338,6 +338,11 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> int result, inquiry_len, inq_result_len = 256;
> char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
>
> + if (!inq_result) {
> + kfree(inq_result);
> + return -ENOMEM;
> + }
> +
> shost_for_each_device(sdev, shost) {
> inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
>
> @@ -366,6 +371,7 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> }
>
> kfree(inq_result);
> + return 0;
> }
>
> static void virtscsi_handle_event(struct work_struct *work)
> @@ -374,12 +380,15 @@ static void virtscsi_handle_event(struct work_struct *work)
> container_of(work, struct virtio_scsi_event_node, work);
> struct virtio_scsi *vscsi = event_node->vscsi;
> struct virtio_scsi_event *event = &event_node->event;
> + int ret = 0;
>
dropped = 0 here
> if (event->event &
> cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
and moved declaration here.
> event->event &= ~cpu_to_virtio32(vscsi->vdev,
> VIRTIO_SCSI_T_EVENTS_MISSED);
> - virtscsi_rescan_hotunplug(vscsi);
> + ret = virtscsi_rescan_hotunplug(vscsi);
> + if (ret)
> + return;
> scsi_scan_host(virtio_scsi_host(vscsi->vdev));
> }
>
> --
> 2.25.1
>
>
Michael S. Tsirkin <[email protected]> 于2023年2月13日周一 20:09写道：
>
> On Thu, Feb 02, 2023 at 02:41:24PM +0800, Zheng Wang wrote:
> > There is no check about the return value of kmalloc in
> > virtscsi_rescan_hotunplug. Add the check to avoid use
> > of null pointer 'inq_result' in case of the failure
> > of kmalloc.
> >
> > Signed-off-by: Zheng Wang <[email protected]>
> > ---
>
> I fixed a typo in subject and tweaked the patch a bit
Thanks for your kindness ^^
>
> > v2:
> > - add kfree to avoid memory leak
> > ---
> > drivers/scsi/virtio_scsi.c | 13 +++++++++++--
> > 1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> > index d07d24c06b54..a66d8815d738 100644
> > --- a/drivers/scsi/virtio_scsi.c
> > +++ b/drivers/scsi/virtio_scsi.c
> > @@ -330,7 +330,7 @@ static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
> > scsi_device_put(sdev);
> > }
> >
> > -static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> > +static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> > {
> > struct scsi_device *sdev;
> > struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
> > @@ -338,6 +338,11 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> > int result, inquiry_len, inq_result_len = 256;
> > char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
> >
> > + if (!inq_result) {
> > + kfree(inq_result);
> > + return -ENOMEM;
> > + }
> > +
> > shost_for_each_device(sdev, shost) {
> > inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
> >
> > @@ -366,6 +371,7 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
> > }
> >
> > kfree(inq_result);
> > + return 0;
> > }
> >
> > static void virtscsi_handle_event(struct work_struct *work)
> > @@ -374,12 +380,15 @@ static void virtscsi_handle_event(struct work_struct *work)
> > container_of(work, struct virtio_scsi_event_node, work);
> > struct virtio_scsi *vscsi = event_node->vscsi;
> > struct virtio_scsi_event *event = &event_node->event;
> > + int ret = 0;
> >
>
> dropped = 0 here
Get it.
>
> > if (event->event &
> > cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
>
> and moved declaration here.
Will do in the next version of patch.
>
> > event->event &= ~cpu_to_virtio32(vscsi->vdev,
> > VIRTIO_SCSI_T_EVENTS_MISSED);
> > - virtscsi_rescan_hotunplug(vscsi);
> > + ret = virtscsi_rescan_hotunplug(vscsi);
> > + if (ret)
> > + return;
> > scsi_scan_host(virtio_scsi_host(vscsi->vdev));
> > }
> >
> > --
> > 2.25.1
> >
> >
>
On Mon, Feb 13, 2023 at 07:09:50AM -0500, Michael S. Tsirkin wrote:
> On Thu, Feb 02, 2023 at 02:41:24PM +0800, Zheng Wang wrote:
> > There is no check about the return value of kmalloc in
> > virtscsi_rescan_hotunplug. Add the check to avoid use
> > of null pointer 'inq_result' in case of the failure
> > of kmalloc.
> >
> > Signed-off-by: Zheng Wang <[email protected]>
> > ---
>
> I fixed a typo in subject and tweaked the patch a bit
Thanks for picking this patch up.
https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git/commit/?h=linux-next&id=4a8fc6e3ac68ce4c355d1f4473ef1d8468b23bdc
Stefan
Get it ^^
Thanks,
Zheng
Stefan Hajnoczi <[email protected]> 于2023年2月15日周三 00:42写道：
>
> On Mon, Feb 13, 2023 at 07:09:50AM -0500, Michael S. Tsirkin wrote:
> > On Thu, Feb 02, 2023 at 02:41:24PM +0800, Zheng Wang wrote:
> > > There is no check about the return value of kmalloc in
> > > virtscsi_rescan_hotunplug. Add the check to avoid use
> > > of null pointer 'inq_result' in case of the failure
> > > of kmalloc.
> > >
> > > Signed-off-by: Zheng Wang <[email protected]>
> > > ---
> >
> > I fixed a typo in subject and tweaked the patch a bit
>
> Thanks for picking this patch up.
> https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git/commit/?h=linux-next&id=4a8fc6e3ac68ce4c355d1f4473ef1d8468b23bdc
>
> Stefan