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@xxxxxxxxxx/ Best regards, Zheng Wang Zheng Wang <zyytlz.wz@xxxxxxx> 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@xxxxxxx> > --- > 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 >
