Message ID | 20200304111117.3540-1-maz@kernel.org (mailing list archive) |
---|---|
State | Mainlined |
Commit | 65ac74f1de3334852fb7d9b1b430fa5a06524276 |
Headers | show |
Series | [v2] iommu/dma: Fix MSI reservation allocation | expand |
On 04/03/2020 11:11 am, Marc Zyngier wrote: > The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page > structures doesn't match the way iommu_put_dma_cookie() frees them. > > The former performs a single allocation of all the required structures, > while the latter tries to free them one at a time. It doesn't quite > work for the main use case (the GICv3 ITS where the range is 64kB) > when the base granule size is 4kB. > > This leads to a nice slab corruption on teardown, which is easily > observable by simply creating a VF on a SRIOV-capable device, and > tearing it down immediately (no need to even make use of it). > Fortunately, this only affects systems where the ITS isn't translated > by the SMMU, which are both rare and non-standard. > > Fix it by allocating iommu_dma_msi_page structures one at a time. Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions") > Signed-off-by: Marc Zyngier <maz@kernel.org> > Reviewed-by: Eric Auger <eric.auger@redhat.com> > Cc: Robin Murphy <robin.murphy@arm.com> > Cc: Joerg Roedel <jroedel@suse.de> > Cc: Will Deacon <will@kernel.org> > Cc: stable@vger.kernel.org > --- > * From v1: > - Got rid of the superfluous error handling (Robin) > - Clarified that it only affects a very small set of systems > - Added Eric's RB (which I assume still stands) > > drivers/iommu/dma-iommu.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index a2e96a5fd9a7..ba128d1cdaee 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -177,15 +177,15 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, > start -= iova_offset(iovad, start); > num_pages = iova_align(iovad, end - start) >> iova_shift(iovad); > > - msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL); > - if (!msi_page) > - return -ENOMEM; > - > for (i = 0; i < num_pages; i++) { > - msi_page[i].phys = start; > - msi_page[i].iova = start; > - INIT_LIST_HEAD(&msi_page[i].list); > - list_add(&msi_page[i].list, &cookie->msi_page_list); > + msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL); > + if (!msi_page) > + return -ENOMEM; > + > + msi_page->phys = start; > + msi_page->iova = start; > + INIT_LIST_HEAD(&msi_page->list); > + list_add(&msi_page->list, &cookie->msi_page_list); > start += iovad->granule; > } > >
On Wed, Mar 04, 2020 at 11:11:17AM +0000, Marc Zyngier wrote: > The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page > structures doesn't match the way iommu_put_dma_cookie() frees them. > > The former performs a single allocation of all the required structures, > while the latter tries to free them one at a time. It doesn't quite > work for the main use case (the GICv3 ITS where the range is 64kB) > when the base granule size is 4kB. > > This leads to a nice slab corruption on teardown, which is easily > observable by simply creating a VF on a SRIOV-capable device, and > tearing it down immediately (no need to even make use of it). > Fortunately, this only affects systems where the ITS isn't translated > by the SMMU, which are both rare and non-standard. > > Fix it by allocating iommu_dma_msi_page structures one at a time. > > Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions") > Signed-off-by: Marc Zyngier <maz@kernel.org> > Reviewed-by: Eric Auger <eric.auger@redhat.com> > Cc: Robin Murphy <robin.murphy@arm.com> > Cc: Joerg Roedel <jroedel@suse.de> > Cc: Will Deacon <will@kernel.org> > Cc: stable@vger.kernel.org Applied for v5.6, thanks.
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index a2e96a5fd9a7..ba128d1cdaee 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -177,15 +177,15 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, start -= iova_offset(iovad, start); num_pages = iova_align(iovad, end - start) >> iova_shift(iovad); - msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL); - if (!msi_page) - return -ENOMEM; - for (i = 0; i < num_pages; i++) { - msi_page[i].phys = start; - msi_page[i].iova = start; - INIT_LIST_HEAD(&msi_page[i].list); - list_add(&msi_page[i].list, &cookie->msi_page_list); + msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL); + if (!msi_page) + return -ENOMEM; + + msi_page->phys = start; + msi_page->iova = start; + INIT_LIST_HEAD(&msi_page->list); + list_add(&msi_page->list, &cookie->msi_page_list); start += iovad->granule; }