From: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Date: Thu, 14 Nov 2013 22:31:19 +0000 (-0800)
Subject: xtensa: fix potential NULL-pointer dereference
X-Git-Tag: upstream/snapshot3+hdmi~3973^2~55
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f8c6d30b766fc8eb83f5b7983ff8a5a9b3189365;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

xtensa: fix potential NULL-pointer dereference

Add missing check for memory allocation fail.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/xtensa/include/asm/pgalloc.h b/arch/xtensa/include/asm/pgalloc.h
index cf914c8..037671a 100644
--- a/arch/xtensa/include/asm/pgalloc.h
+++ b/arch/xtensa/include/asm/pgalloc.h
@@ -51,9 +51,13 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
 					unsigned long addr)
 {
+	pte_t *pte;
 	struct page *page;
 
-	page = virt_to_page(pte_alloc_one_kernel(mm, addr));
+	pte = pte_alloc_one_kernel(mm, addr);
+	if (!pte)
+		return NULL;
+	page = virt_to_page(pte);
 	pgtable_page_ctor(page);
 	return page;
 }