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 Move incrementing iova to the caller of these functions as part of preparing to handle end of address space map/unmap. Signed-off-by: Alex Mastro --- drivers/vfio/vfio_iommu_type1.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 1ac056b27f27..48b84a7af2e1 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -1013,7 +1013,7 @@ static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain, #define VFIO_IOMMU_TLB_SYNC_MAX 512 static size_t unmap_unpin_fast(struct vfio_domain *domain, - struct vfio_dma *dma, dma_addr_t *iova, + struct vfio_dma *dma, dma_addr_t iova, size_t len, phys_addr_t phys, long *unlocked, struct list_head *unmapped_list, int *unmapped_cnt, @@ -1023,18 +1023,17 @@ static size_t unmap_unpin_fast(struct vfio_domain *domain, struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (entry) { - unmapped = iommu_unmap_fast(domain->domain, *iova, len, + unmapped = iommu_unmap_fast(domain->domain, iova, len, iotlb_gather); if (!unmapped) { kfree(entry); } else { - entry->iova = *iova; + entry->iova = iova; entry->phys = phys; entry->len = unmapped; list_add_tail(&entry->list, unmapped_list); - *iova += unmapped; (*unmapped_cnt)++; } } @@ -1053,18 +1052,17 @@ static size_t unmap_unpin_fast(struct vfio_domain *domain, } static size_t unmap_unpin_slow(struct vfio_domain *domain, - struct vfio_dma *dma, dma_addr_t *iova, + struct vfio_dma *dma, dma_addr_t iova, size_t len, phys_addr_t phys, long *unlocked) { - size_t unmapped = iommu_unmap(domain->domain, *iova, len); + size_t unmapped = iommu_unmap(domain->domain, iova, len); if (unmapped) { - *unlocked += vfio_unpin_pages_remote(dma, *iova, + *unlocked += vfio_unpin_pages_remote(dma, iova, phys >> PAGE_SHIFT, unmapped >> PAGE_SHIFT, false); - *iova += unmapped; cond_resched(); } return unmapped; @@ -1127,16 +1125,18 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, * First, try to use fast unmap/unpin. In case of failure, * switch to slow unmap/unpin path. */ - unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys, + unmapped = unmap_unpin_fast(domain, dma, iova, len, phys, &unlocked, &unmapped_region_list, &unmapped_region_cnt, &iotlb_gather); if (!unmapped) { - unmapped = unmap_unpin_slow(domain, dma, &iova, len, + unmapped = unmap_unpin_slow(domain, dma, iova, len, phys, &unlocked); if (WARN_ON(!unmapped)) break; } + + iova += unmapped; } dma->iommu_mapped = false; -- 2.47.3 Handle DMA map/unmap operations up to the addressable limit by comparing against inclusive end-of-range limits, and changing iteration to perform relative traversals across range sizes, rather than absolute traversals across addresses. vfio_link_dma inserts a zero-sized vfio_dma into the rb-tree, and is only used for that purpose, so discard the size from consideration for the insertion point. Signed-off-by: Alex Mastro --- drivers/vfio/vfio_iommu_type1.c | 77 ++++++++++++++++++++++------------------- 1 file changed, 42 insertions(+), 35 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 48b84a7af2e1..a65625dcf708 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -166,12 +166,14 @@ static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu, { struct rb_node *node = iommu->dma_list.rb_node; + WARN_ON(!size); + while (node) { struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); - if (start + size <= dma->iova) + if (start + size - 1 < dma->iova) node = node->rb_left; - else if (start >= dma->iova + dma->size) + else if (start > dma->iova + dma->size - 1) node = node->rb_right; else return dma; @@ -181,16 +183,19 @@ 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, size_t size) + dma_addr_t start, + dma_addr_t end) { struct rb_node *res = NULL; struct rb_node *node = iommu->dma_list.rb_node; struct vfio_dma *dma_res = NULL; + WARN_ON(end < start); + while (node) { struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); - if (start < dma->iova + dma->size) { + if (start <= dma->iova + dma->size - 1) { res = node; dma_res = dma; if (start >= dma->iova) @@ -200,7 +205,7 @@ static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu, node = node->rb_right; } } - if (res && size && dma_res->iova >= start + size) + if (res && dma_res->iova > end) res = NULL; return res; } @@ -210,11 +215,13 @@ static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new) struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL; struct vfio_dma *dma; + WARN_ON(new->size != 0); + while (*link) { parent = *link; dma = rb_entry(parent, struct vfio_dma, node); - if (new->iova + new->size <= dma->iova) + if (new->iova <= dma->iova) link = &(*link)->rb_left; else link = &(*link)->rb_right; @@ -1071,12 +1078,12 @@ static size_t unmap_unpin_slow(struct vfio_domain *domain, static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, bool do_accounting) { - dma_addr_t iova = dma->iova, end = dma->iova + dma->size; struct vfio_domain *domain, *d; LIST_HEAD(unmapped_region_list); struct iommu_iotlb_gather iotlb_gather; int unmapped_region_cnt = 0; long unlocked = 0; + size_t pos = 0; if (!dma->size) return 0; @@ -1100,13 +1107,14 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, } iommu_iotlb_gather_init(&iotlb_gather); - while (iova < end) { + while (pos < dma->size) { size_t unmapped, len; phys_addr_t phys, next; + dma_addr_t iova = dma->iova + pos; phys = iommu_iova_to_phys(domain->domain, iova); if (WARN_ON(!phys)) { - iova += PAGE_SIZE; + pos += PAGE_SIZE; continue; } @@ -1115,7 +1123,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, * may require hardware cache flushing, try to find the * largest contiguous physical memory chunk to unmap. */ - for (len = PAGE_SIZE; iova + len < end; len += PAGE_SIZE) { + for (len = PAGE_SIZE; pos + len < dma->size; len += PAGE_SIZE) { next = iommu_iova_to_phys(domain->domain, iova + len); if (next != phys + len) break; @@ -1136,7 +1144,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, break; } - iova += unmapped; + pos += unmapped; } dma->iommu_mapped = false; @@ -1228,7 +1236,7 @@ static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, } static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, - dma_addr_t iova, size_t size, size_t pgsize) + dma_addr_t iova, dma_addr_t iova_end, size_t pgsize) { struct vfio_dma *dma; struct rb_node *n; @@ -1245,8 +1253,8 @@ static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, if (dma && dma->iova != iova) return -EINVAL; - dma = vfio_find_dma(iommu, iova + size - 1, 0); - if (dma && dma->iova + dma->size != iova + size) + dma = vfio_find_dma(iommu, iova_end, 1); + if (dma && dma->iova + dma->size - 1 != iova_end) return -EINVAL; for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { @@ -1255,7 +1263,7 @@ static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, if (dma->iova < iova) continue; - if (dma->iova > iova + size - 1) + if (dma->iova > iova_end) break; ret = update_user_bitmap(bitmap, iommu, dma, iova, pgsize); @@ -1348,7 +1356,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (unmap_all) { if (iova || size) goto unlock; - size = SIZE_MAX; + iova_end = ~(dma_addr_t)0; } else { if (!size || size & (pgsize - 1)) goto unlock; @@ -1403,17 +1411,17 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (dma && dma->iova != iova) goto unlock; - dma = vfio_find_dma(iommu, iova_end, 0); - if (dma && dma->iova + dma->size != iova + size) + dma = vfio_find_dma(iommu, iova_end, 1); + if (dma && dma->iova + dma->size - 1 != iova_end) goto unlock; } ret = 0; - n = first_n = vfio_find_dma_first_node(iommu, iova, size); + n = first_n = vfio_find_dma_first_node(iommu, iova, iova_end); while (n) { dma = rb_entry(n, struct vfio_dma, node); - if (dma->iova >= iova + size) + if (dma->iova > iova_end) break; if (!iommu->v2 && iova > dma->iova) @@ -1743,12 +1751,12 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu, for (; n; n = rb_next(n)) { struct vfio_dma *dma; - dma_addr_t iova; + size_t pos = 0; dma = rb_entry(n, struct vfio_dma, node); - iova = dma->iova; - while (iova < dma->iova + dma->size) { + while (pos < dma->size) { + dma_addr_t iova = dma->iova + pos; phys_addr_t phys; size_t size; @@ -1764,14 +1772,14 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu, phys = iommu_iova_to_phys(d->domain, iova); if (WARN_ON(!phys)) { - iova += PAGE_SIZE; + pos += PAGE_SIZE; continue; } size = PAGE_SIZE; p = phys + size; i = iova + size; - while (i < dma->iova + dma->size && + while (pos + size < dma->size && p == iommu_iova_to_phys(d->domain, i)) { size += PAGE_SIZE; p += PAGE_SIZE; @@ -1779,9 +1787,8 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu, } } else { unsigned long pfn; - unsigned long vaddr = dma->vaddr + - (iova - dma->iova); - size_t n = dma->iova + dma->size - iova; + unsigned long vaddr = dma->vaddr + pos; + size_t n = dma->size - pos; long npage; npage = vfio_pin_pages_remote(dma, vaddr, @@ -1812,7 +1819,7 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu, goto unwind; } - iova += size; + pos += size; } } @@ -1829,29 +1836,29 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu, unwind: for (; n; n = rb_prev(n)) { struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); - dma_addr_t iova; + size_t pos = 0; if (dma->iommu_mapped) { iommu_unmap(domain->domain, dma->iova, dma->size); continue; } - iova = dma->iova; - while (iova < dma->iova + dma->size) { + while (pos < dma->size) { + dma_addr_t iova = dma->iova + pos; phys_addr_t phys, p; size_t size; dma_addr_t i; phys = iommu_iova_to_phys(domain->domain, iova); if (!phys) { - iova += PAGE_SIZE; + pos += PAGE_SIZE; continue; } size = PAGE_SIZE; p = phys + size; i = iova + size; - while (i < dma->iova + dma->size && + while (pos + size < dma->size && p == iommu_iova_to_phys(domain->domain, i)) { size += PAGE_SIZE; p += PAGE_SIZE; @@ -2989,7 +2996,7 @@ static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, if (iommu->dirty_page_tracking) ret = vfio_iova_dirty_bitmap(range.bitmap.data, - iommu, iova, size, + iommu, iova, iova_end, range.bitmap.pgsize); else ret = -EINVAL; -- 2.47.3