From: Jason Gunthorpe Date: Fri, 27 Mar 2026 15:22:10 +0000 (-0300) Subject: iommu/riscv: Remove overflows on the invalidation path X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=40a13b49957937427bc23e78eb50679df4396a47;p=thirdparty%2Flinux.git iommu/riscv: Remove overflows on the invalidation path Since RISC-V supports a sign extended page table it should support a gather->end of ULONG_MAX, but if this happens it will infinite loop because of the overflow. Also avoid overflow computing the length by moving the +1 to the other side of the < Fixes: 488ffbf18171 ("iommu/riscv: Paging domain support") Signed-off-by: Jason Gunthorpe Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c index 6ac7e3edef8aa..3ec99c979d473 100644 --- a/drivers/iommu/riscv/iommu.c +++ b/drivers/iommu/riscv/iommu.c @@ -931,8 +931,6 @@ static void riscv_iommu_iotlb_inval(struct riscv_iommu_domain *domain, struct riscv_iommu_bond *bond; struct riscv_iommu_device *iommu, *prev; struct riscv_iommu_command cmd; - unsigned long len = end - start + 1; - unsigned long iova; /* * For each IOMMU linked with this protection domain (via bonds->dev), @@ -975,11 +973,14 @@ static void riscv_iommu_iotlb_inval(struct riscv_iommu_domain *domain, riscv_iommu_cmd_inval_vma(&cmd); riscv_iommu_cmd_inval_set_pscid(&cmd, domain->pscid); - if (len && len < RISCV_IOMMU_IOTLB_INVAL_LIMIT) { - for (iova = start; iova < end; iova += PAGE_SIZE) { + if (end - start < RISCV_IOMMU_IOTLB_INVAL_LIMIT - 1) { + unsigned long iova = start; + + do { riscv_iommu_cmd_inval_set_addr(&cmd, iova); riscv_iommu_cmd_send(iommu, &cmd); - } + } while (!check_add_overflow(iova, PAGE_SIZE, &iova) && + iova < end); } else { riscv_iommu_cmd_send(iommu, &cmd); }