From 3b8ecccd3be89ba3929053d283cdce9799379ee2 Mon Sep 17 00:00:00 2001 From: Lijun Fang Date: Tue, 21 May 2019 17:29:55 +0800 Subject: [PATCH] mm/cdm: new_pol can be NULL when mbind mode arg was MPOL_DEFAULT hulk inclusion category: bugfix bugzilla: 16080 CVE: NA ------------------- the pointer new_pol can be NULL when mbind() mode arg was MPOL_DEFAULT, so, before using new_pol, make sure it was not NULL. Fixes: a72a680ff761 ("mm: Tag VMA with VM_CDM flag explicitly during mbind(MPOL_BIND) and page fault") Signed-off-by: Lijun Fang Reviewed-by: Yang Yingliang Signed-off-by: Yang Yingliang --- mm/mempolicy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d4592b9a5b9d..c73ae1f9175b 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -763,8 +763,8 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, vmstart = max(start, vma->vm_start); vmend = min(end, vma->vm_end); - if ((new_pol->mode == MPOL_BIND) - && nodemask_has_cdm(new_pol->v.nodes)) + if (new_pol && (new_pol->mode == MPOL_BIND) && + nodemask_has_cdm(new_pol->v.nodes)) set_vm_cdm(vma); if (mpol_equal(vma_policy(vma), new_pol)) -- GitLab