diff options
| -rw-r--r-- | mm/shmem.c | 18 | ||||
| -rw-r--r-- | mm/userfaultfd.c | 26 |
2 files changed, 40 insertions, 4 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 6c54a6874e41..99d5867daadb 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2216,6 +2216,7 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, struct page *page; pte_t _dst_pte, *dst_pte; int ret; + pgoff_t offset, max_off; ret = -ENOMEM; if (!shmem_inode_acct_block(inode, 1)) @@ -2253,6 +2254,12 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, __SetPageSwapBacked(page); __SetPageUptodate(page); + ret = -EFAULT; + offset = linear_page_index(dst_vma, dst_addr); + max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + if (unlikely(offset >= max_off)) + goto out_release; + ret = mem_cgroup_try_charge_delay(page, dst_mm, gfp, &memcg, false); if (ret) goto out_release; @@ -2268,8 +2275,14 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, if (dst_vma->vm_flags & VM_WRITE) _dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte)); - ret = -EEXIST; dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl); + + ret = -EFAULT; + max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + if (unlikely(offset >= max_off)) + goto out_release_uncharge_unlock; + + ret = -EEXIST; if (!pte_none(*dst_pte)) goto out_release_uncharge_unlock; @@ -2287,13 +2300,14 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, /* No need to invalidate - it was non-present before */ update_mmu_cache(dst_vma, dst_addr, dst_pte); - unlock_page(page); pte_unmap_unlock(dst_pte, ptl); + unlock_page(page); ret = 0; out: return ret; out_release_uncharge_unlock: pte_unmap_unlock(dst_pte, ptl); + delete_from_page_cache(page); out_release_uncharge: mem_cgroup_cancel_charge(page, memcg, false); out_release: diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 43cf314cfddd..458acda96f20 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -33,6 +33,8 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm, void *page_kaddr; int ret; struct page *page; + pgoff_t offset, max_off; + struct inode *inode; if (!*pagep) { ret = -ENOMEM; @@ -73,8 +75,17 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm, if (dst_vma->vm_flags & VM_WRITE) _dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte)); - ret = -EEXIST; dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl); + if (dst_vma->vm_file) { + /* the shmem MAP_PRIVATE case requires checking the i_size */ + inode = dst_vma->vm_file->f_inode; + offset = linear_page_index(dst_vma, dst_addr); + max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + ret = -EFAULT; + if (unlikely(offset >= max_off)) + goto out_release_uncharge_unlock; + } + ret = -EEXIST; if (!pte_none(*dst_pte)) goto out_release_uncharge_unlock; @@ -108,11 +119,22 @@ static int mfill_zeropage_pte(struct mm_struct *dst_mm, pte_t _dst_pte, *dst_pte; spinlock_t *ptl; int ret; + pgoff_t offset, max_off; + struct inode *inode; _dst_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr), dst_vma->vm_page_prot)); - ret = -EEXIST; dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl); + if (dst_vma->vm_file) { + /* the shmem MAP_PRIVATE case requires checking the i_size */ + inode = dst_vma->vm_file->f_inode; + offset = linear_page_index(dst_vma, dst_addr); + max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + ret = -EFAULT; + if (unlikely(offset >= max_off)) + goto out_unlock; + } + ret = -EEXIST; if (!pte_none(*dst_pte)) goto out_unlock; set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); |