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Diffstat (limited to 'arch/um/kernel/skas/uaccess.c')
-rw-r--r--arch/um/kernel/skas/uaccess.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index 3236052f20e6..d617f8dc9c19 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -17,6 +17,7 @@
pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
@@ -27,7 +28,11 @@ pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
if (!pgd_present(*pgd))
return NULL;
- pud = pud_offset(pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ if (!p4d_present(*p4d))
+ return NULL;
+
+ pud = pud_offset(p4d, addr);
if (!pud_present(*pud))
return NULL;