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 ganule 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).
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 Cc: Robin Murphy robin.murphy@arm.com Cc: Joerg Roedel jroedel@suse.de Cc: Eric Auger eric.auger@redhat.com Cc: Will Deacon will@kernel.org Cc: stable@vger.kernel.org --- drivers/iommu/dma-iommu.c | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index a2e96a5fd9a7..01fa64856c12 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -171,25 +171,37 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, phys_addr_t start, phys_addr_t end) { struct iova_domain *iovad = &cookie->iovad; - struct iommu_dma_msi_page *msi_page; - int i, num_pages; + struct iommu_dma_msi_page *msi_page, *tmp; + int i, num_pages, ret = 0; + phys_addr_t base;
- start -= iova_offset(iovad, start); + base = 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) { + ret = -ENOMEM; + break; + } + 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; }
- return 0; + if (ret) { + list_for_each_entry_safe(msi_page, tmp, + &cookie->msi_page_list, list) { + if (msi_page->phys >= base && msi_page->phys < start) { + list_del(&msi_page->list); + kfree(msi_page); + } + } + } + + return ret; }
static int iova_reserve_pci_windows(struct pci_dev *dev,