Messages in this thread | | | Date | Tue, 28 Mar 2023 08:48:55 -0700 | From | Jacob Pan <> | Subject | Re: [PATCH v2 7/8] iommu: Export iommu_get_dma_domain |
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Hi Baolu,
On Tue, 28 Mar 2023 14:04:15 +0800, Baolu Lu <baolu.lu@linux.intel.com> wrote:
> On 3/28/23 7:21 AM, Jacob Pan wrote: > > Devices that use ENQCMDS to submit work needs to retrieve its DMA > > domain. It can then attach PASID to the DMA domain for shared mapping > > (with RID) established by DMA API. > > > > Signed-off-by: Jacob Pan<jacob.jun.pan@linux.intel.com> > > --- > > drivers/iommu/iommu.c | 1 + > > include/linux/iommu.h | 5 +++++ > > 2 files changed, 6 insertions(+) > > > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > index 10db680acaed..c51d343a75d2 100644 > > --- a/drivers/iommu/iommu.c > > +++ b/drivers/iommu/iommu.c > > @@ -2118,6 +2118,7 @@ struct iommu_domain *iommu_get_dma_domain(struct > > device *dev) { > > return dev->iommu_group->default_domain; > > } > > +EXPORT_SYMBOL_GPL(iommu_get_dma_domain); > > Directly exporting this function for external use seems unsafe. If the > caller is the kernel driver for this device, it's fine because default > domain remains unchanged during the life cycle of the driver. Otherwise, > using this function may cause UAF. Keep in mind that group's default > domain could be changed through sysfs. don't you have to unload the driver?
> However, iommu_get_domain_for_dev() has already done so and has been > exported. Maybe I'm worried too much. :-) > > Best regards, > baolu
Thanks,
Jacob
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