Commit 4ca4ac49 authored by ZhangPeng's avatar ZhangPeng Committed by Ma Wupeng
Browse files

userswap: add VMA check for swap-in and swap-out buffer 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6CAIM



--------------------------------

Add VMA check for swap-in and swap-out buffer to make sure that swap-in
and swap-out buffer is of the same type as swap-out VA.

Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent b9d83c98

mm/userswap.c

+7 −4
Original line number Diff line number Diff line
@@ -19,9 +19,9 @@ DEFINE_STATIC_KEY_FALSE(userswap_enabled); 


static bool vma_uswap_compatible(struct vm_area_struct *vma)

{

	if (!vma || !(vma->vm_flags & VM_USWAP) || !vma_is_anonymous(vma) ||

	    vma->vm_file || vma->vm_flags & (VM_SHARED | VM_LOCKED | VM_STACK |

					     VM_IO | VM_PFNMAP))

	if (!vma || !vma_is_anonymous(vma) || vma->vm_file ||

	    vma->vm_flags & (VM_SHARED | VM_LOCKED | VM_STACK | VM_IO |

	    VM_PFNMAP | VM_HUGETLB))

		return false;

	return true;

}
@@ -93,6 +93,7 @@ static unsigned long pages_can_be_swapped(struct mm_struct *mm, 
	while (addr < addr_end) {

		vma = find_vma(mm, addr);

		if (!vma || addr < vma->vm_start ||

		    !(vma->vm_flags & VM_USWAP) ||

		    !vma_uswap_compatible(vma)) {

			ret = -EINVAL;

			goto out_err;
@@ -309,6 +310,8 @@ static unsigned long do_user_swap(struct mm_struct *mm, 
		new_vma = find_vma(mm, new_addr);

		if (!new_vma || new_addr < new_vma->vm_start)

			goto out_recover;

		if (!vma_uswap_compatible(new_vma))

			goto out_recover;



		ret = -EACCES;

		if (!(old_vma->vm_flags & VM_WRITE) &&
@@ -409,7 +412,7 @@ int mfill_atomic_pte_nocopy(struct mm_struct *mm, 
	if (!src_vma || src_addr < src_vma->vm_start)

		return -EINVAL;



	if (src_vma->vm_flags & VM_LOCKED)

	if (!vma_uswap_compatible(src_vma))

		return -EINVAL;



	page = follow_page(src_vma, src_addr, FOLL_GET | FOLL_MIGRATION);