Adopt check_*_overflow functions to clearly express overflow check intent. Signed-off-by: Alex Mastro --- drivers/vfio/vfio_iommu_type1.c | 86 ++++++++++++++++++++++++++++++----------- 1 file changed, 63 insertions(+), 23 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index f8d68fe77b41..1ac056b27f27 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "vfio.h" #define DRIVER_VERSION "0.2" @@ -180,7 +181,7 @@ static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu, } static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu, - dma_addr_t start, u64 size) + dma_addr_t start, size_t size) { struct rb_node *res = NULL; struct rb_node *node = iommu->dma_list.rb_node; @@ -825,14 +826,20 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, unsigned long remote_vaddr; struct vfio_dma *dma; bool do_accounting; + dma_addr_t iova_end; + size_t iova_size; - if (!iommu || !pages) + if (!iommu || !pages || npage <= 0) return -EINVAL; /* Supported for v2 version only */ if (!iommu->v2) return -EACCES; + if (check_mul_overflow(npage, PAGE_SIZE, &iova_size) || + check_add_overflow(user_iova, iova_size - 1, &iova_end)) + return -EOVERFLOW; + mutex_lock(&iommu->lock); if (WARN_ONCE(iommu->vaddr_invalid_count, @@ -938,12 +945,21 @@ static void vfio_iommu_type1_unpin_pages(void *iommu_data, { struct vfio_iommu *iommu = iommu_data; bool do_accounting; + dma_addr_t iova_end; + size_t iova_size; int i; /* Supported for v2 version only */ if (WARN_ON(!iommu->v2)) return; + if (WARN_ON(npage <= 0)) + return; + + if (WARN_ON(check_mul_overflow(npage, PAGE_SIZE, &iova_size) || + check_add_overflow(user_iova, iova_size - 1, &iova_end))) + return; + mutex_lock(&iommu->lock); do_accounting = list_empty(&iommu->domain_list); @@ -1304,7 +1320,8 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, int ret = -EINVAL, retries = 0; unsigned long pgshift; dma_addr_t iova = unmap->iova; - u64 size = unmap->size; + dma_addr_t iova_end; + size_t size = unmap->size; bool unmap_all = unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL; bool invalidate_vaddr = unmap->flags & VFIO_DMA_UNMAP_FLAG_VADDR; struct rb_node *n, *first_n; @@ -1317,6 +1334,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, goto unlock; } + if (iova != unmap->iova || size != unmap->size) { + ret = -EOVERFLOW; + goto unlock; + } + pgshift = __ffs(iommu->pgsize_bitmap); pgsize = (size_t)1 << pgshift; @@ -1326,10 +1348,15 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (unmap_all) { if (iova || size) goto unlock; - size = U64_MAX; - } else if (!size || size & (pgsize - 1) || - iova + size - 1 < iova || size > SIZE_MAX) { - goto unlock; + size = SIZE_MAX; + } else { + if (!size || size & (pgsize - 1)) + goto unlock; + + if (check_add_overflow(iova, size - 1, &iova_end)) { + ret = -EOVERFLOW; + goto unlock; + } } /* When dirty tracking is enabled, allow only min supported pgsize */ @@ -1376,7 +1403,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (dma && dma->iova != iova) goto unlock; - dma = vfio_find_dma(iommu, iova + size - 1, 0); + dma = vfio_find_dma(iommu, iova_end, 0); if (dma && dma->iova + dma->size != iova + size) goto unlock; } @@ -1578,7 +1605,9 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, { bool set_vaddr = map->flags & VFIO_DMA_MAP_FLAG_VADDR; dma_addr_t iova = map->iova; + dma_addr_t iova_end; unsigned long vaddr = map->vaddr; + unsigned long vaddr_end; size_t size = map->size; int ret = 0, prot = 0; size_t pgsize; @@ -1586,8 +1615,15 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, /* Verify that none of our __u64 fields overflow */ if (map->size != size || map->vaddr != vaddr || map->iova != iova) + return -EOVERFLOW; + + if (!size) return -EINVAL; + if (check_add_overflow(iova, size - 1, &iova_end) || + check_add_overflow(vaddr, size - 1, &vaddr_end)) + return -EOVERFLOW; + /* READ/WRITE from device perspective */ if (map->flags & VFIO_DMA_MAP_FLAG_WRITE) prot |= IOMMU_WRITE; @@ -1603,13 +1639,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, WARN_ON((pgsize - 1) & PAGE_MASK); - if (!size || (size | iova | vaddr) & (pgsize - 1)) { - ret = -EINVAL; - goto out_unlock; - } - - /* Don't allow IOVA or virtual address wrap */ - if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) { + if ((size | iova | vaddr) & (pgsize - 1)) { ret = -EINVAL; goto out_unlock; } @@ -1640,7 +1670,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, goto out_unlock; } - if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) { + if (!vfio_iommu_iova_dma_valid(iommu, iova, iova_end)) { ret = -EINVAL; goto out_unlock; } @@ -2907,7 +2937,8 @@ static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, struct vfio_iommu_type1_dirty_bitmap_get range; unsigned long pgshift; size_t data_size = dirty.argsz - minsz; - size_t iommu_pgsize; + size_t size, iommu_pgsize; + dma_addr_t iova, iova_end; if (!data_size || data_size < sizeof(range)) return -EINVAL; @@ -2916,14 +2947,24 @@ static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, sizeof(range))) return -EFAULT; - if (range.iova + range.size < range.iova) + iova = range.iova; + size = range.size; + + if (iova != range.iova || size != range.size) + return -EOVERFLOW; + + if (!size) return -EINVAL; + + if (check_add_overflow(iova, size - 1, &iova_end)) + return -EOVERFLOW; + if (!access_ok((void __user *)range.bitmap.data, range.bitmap.size)) return -EINVAL; pgshift = __ffs(range.bitmap.pgsize); - ret = verify_bitmap_size(range.size >> pgshift, + ret = verify_bitmap_size(size >> pgshift, range.bitmap.size); if (ret) return ret; @@ -2937,19 +2978,18 @@ static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, ret = -EINVAL; goto out_unlock; } - if (range.iova & (iommu_pgsize - 1)) { + if (iova & (iommu_pgsize - 1)) { ret = -EINVAL; goto out_unlock; } - if (!range.size || range.size & (iommu_pgsize - 1)) { + if (size & (iommu_pgsize - 1)) { ret = -EINVAL; goto out_unlock; } if (iommu->dirty_page_tracking) ret = vfio_iova_dirty_bitmap(range.bitmap.data, - iommu, range.iova, - range.size, + iommu, iova, size, range.bitmap.pgsize); else ret = -EINVAL; -- 2.47.3