From 6c797e3418a08601f451b75ce1dd219da5f4c850 Mon Sep 17 00:00:00 2001
From: Lijun Fang <fanglijun3@huawei.com>
Date: Mon, 20 May 2019 16:47:00 +0800
Subject: [PATCH] mm/cdm: Fix bug when the vma can be NULL pointer, in
 mark_vma_cdm().

hulk inclusion
category: bugfix
bugzilla: 16069
CVE: NA
-------------------

alloc_page_vma() can be called by try_to_unuse(), in this case,
the vma is NULL.

Signed-off-by: Lijun Fang <fanglijun3@huawei.com>
Reviewed-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 mm/mempolicy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index e3ab1d942dd4..d4592b9a5b9d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -178,7 +178,7 @@ static inline void clr_vm_cdm(struct vm_area_struct *vma)
 static void mark_vma_cdm(nodemask_t *nmask,
 		struct page *page, struct vm_area_struct *vma)
 {
-	if (!page)
+	if (!page || !vma)
 		return;
 
 	if (vma->vm_flags & VM_CDM)
-- 
GitLab