From: Jason Gunthorpe Date: Fri, 30 Aug 2024 00:06:13 +0000 (-0300) Subject: iommu/amd: Remove amd_iommu_domain_update() from page table freeing X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=322d889ae7d39f8538a6deac35869aa3be1855bd;p=linux-block.git iommu/amd: Remove amd_iommu_domain_update() from page table freeing It is a serious bug if the domain is still mapped to any DTEs when it is freed as we immediately start freeing page table memory, so any remaining HW touch will UAF. If it is not mapped then dev_list is empty and amd_iommu_domain_update() does nothing. Remove it and add a WARN_ON() to catch this class of bug. Reviewed-by: Vasant Hegde Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/4-v2-831cdc4d00f3+1a315-amd_iopgtbl_jgg@nvidia.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c index 03a3b09f0512..0743b698128d 100644 --- a/drivers/iommu/amd/io_pgtable.c +++ b/drivers/iommu/amd/io_pgtable.c @@ -577,9 +577,6 @@ static void v1_free_pgtable(struct io_pgtable *iop) /* Update data structure */ amd_iommu_domain_clr_pt_root(dom); - - /* Make changes visible to IOMMUs */ - amd_iommu_domain_update(dom); } static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index c90a53a0385d..05ae44f13ec8 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2255,6 +2255,8 @@ void protection_domain_free(struct protection_domain *domain) if (!domain) return; + WARN_ON(!list_empty(&domain->dev_list)); + if (domain->iop.pgtbl_cfg.tlb) free_io_pgtable_ops(&domain->iop.iop.ops);