diff options
| author | Naoya Horiguchi <[email protected]> | 2014-04-07 15:36:54 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2014-04-07 16:35:49 -0700 |
| commit | a9af0c5dfdaf0b2e1a8bab7fbf6f29138947d534 (patch) | |
| tree | 2de13aa7095ee0b4aa8a7d47d9d89817a06a52a6 | |
| parent | 87c1b497c299e48e681f041de4dd6ce4831aaf75 (diff) | |
mm/hugetlb.c: add NULL check of return value of huge_pte_offset
huge_pte_offset() could return NULL, so we need NULL check to avoid
potential NULL pointer dereferences.
Signed-off-by: Naoya Horiguchi <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Sasha Levin <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | mm/hugetlb.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7c02b9dadfb0..6cddfadaba03 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2690,7 +2690,8 @@ retry_avoidcopy: BUG_ON(huge_pte_none(pte)); spin_lock(ptl); ptep = huge_pte_offset(mm, address & huge_page_mask(h)); - if (likely(pte_same(huge_ptep_get(ptep), pte))) + if (likely(ptep && + pte_same(huge_ptep_get(ptep), pte))) goto retry_avoidcopy; /* * race occurs while re-acquiring page table @@ -2734,7 +2735,7 @@ retry_avoidcopy: */ spin_lock(ptl); ptep = huge_pte_offset(mm, address & huge_page_mask(h)); - if (likely(pte_same(huge_ptep_get(ptep), pte))) { + if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { ClearPagePrivate(new_page); /* Break COW */ |