mm/hugetlb: check for pte NULL pointer in __page_check_address()

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jianguo Wu 2013-12-18 17:08:59 -08:00 committed by Greg Kroah-Hartman
parent 31eb5f24b9
commit 398bbc5710

View file

@ -600,7 +600,11 @@ pte_t *__page_check_address(struct page *page, struct mm_struct *mm,
spinlock_t *ptl; spinlock_t *ptl;
if (unlikely(PageHuge(page))) { if (unlikely(PageHuge(page))) {
/* when pud is not present, pte will be NULL */
pte = huge_pte_offset(mm, address); pte = huge_pte_offset(mm, address);
if (!pte)
return NULL;
ptl = &mm->page_table_lock; ptl = &mm->page_table_lock;
goto check; goto check;
} }