| Message ID | 20230202064124.22277-1-zyytlz.wz@163.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] scsi: virtio_scsi: Fix poential NULL pointer dereference in virtscsi_rescan_hotunplug | expand |
After writing the patch, I found there is an old patch about this issue. The link is : https://lore.kernel.org/all/ecb2f3c6-af8c-dd43-1dcf-0b5e8a9d8848@redhat.com/ Best regards, Zheng Wang Zheng Wang <zyytlz.wz@163.com> 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 <zyytlz.wz@163.com> > --- > 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 <zyytlz.wz@163.com> > --- 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 <mst@redhat.com> 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 <zyytlz.wz@163.com> > > --- > > 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 <zyytlz.wz@163.com> > > --- > > 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 <stefanha@redhat.com> 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 <zyytlz.wz@163.com> > > > --- > > > > 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
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)); }
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 <zyytlz.wz@163.com> --- v2: - add kfree to avoid memory leak --- drivers/scsi/virtio_scsi.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)