From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
check if vma is null before dereferencing it, this avoiding any
potential null pointer dereferences on vma via the is_vm_hugetlb_page
call or the direct vma->vm_flags reference.
Detected with CoverityScan, CID#1427995 ("Dereference before null check")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
mm/migrate.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 7958dfa01b16..039f7bc3b9ee 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2757,10 +2757,10 @@ int migrate_vma(const struct migrate_vma_ops *ops,
/* Sanity check the arguments */
start &= PAGE_MASK;
end &= PAGE_MASK;
- if (is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL))
- return -EINVAL;
if (!vma || !ops || !src || !dst || start >= end)
return -EINVAL;
+ if (is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL))
+ return -EINVAL;
if (start < vma->vm_start || start >= vma->vm_end)
return -EINVAL;
if (end <= vma->vm_start || end > vma->vm_end)
--
2.11.0
--
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