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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2014-04-08 02:36:54 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-08 03:35:49 +0400 |
| commit | a9af0c5dfdaf0b2e1a8bab7fbf6f29138947d534 (patch) | |
| tree | 2de13aa7095ee0b4aa8a7d47d9d89817a06a52a6 /mm/hugetlb.c | |
| parent | 87c1b497c299e48e681f041de4dd6ce4831aaf75 (diff) | |
| download | linux-a9af0c5dfdaf0b2e1a8bab7fbf6f29138947d534.tar.xz | |
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 <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
| -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 */ |