| From | Luis Henriques <> | Subject | [PATCH 3.5 13/96] mm/hugetlb: check for pte NULL pointer in __page_check_address() | Date | Mon, 13 Jan 2014 14:23:36 +0000 |
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3.5.7.29 -stable review patch. If anyone has any objections, please let me know.
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From: Jianguo Wu <wujianguo@huawei.com>
commit 98398c32f6687ee1e1f3ae084effb4b75adb0747 upstream.
In __page_check_address(), if address's pud is not present, huge_pte_offset() will return NULL, we should check the return value.
Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Cc: qiuxishi <qiuxishi@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [ luis: backported to 3.5: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- mm/rmap.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/mm/rmap.c b/mm/rmap.c index aa95e59..2b03b31 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -623,7 +623,11 @@ pte_t *__page_check_address(struct page *page, struct mm_struct *mm, spinlock_t *ptl; if (unlikely(PageHuge(page))) { + /* when pud is not present, pte will be NULL */ pte = huge_pte_offset(mm, address); + if (!pte) + return NULL; + ptl = &mm->page_table_lock; goto check; } -- 1.8.3.2
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