From: Andrew Morton <akpm@linux-foundation.org>
Date: Mon, 23 Aug 2021 23:59:09 +0000 (+1000)
Subject: mm-gup-fix-potential-pgmap-refcnt-leak-in-__gup_device_huge-fix-fix
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=77dc947e0e0fc039abd6a19c36dcce75003e5b37;p=users%2Fjedix%2Flinux-maple.git

mm-gup-fix-potential-pgmap-refcnt-leak-in-__gup_device_huge-fix-fix

fix return value

Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---

diff --git a/mm/gup.c b/mm/gup.c
index 41fd86ec362c..a10c48ef613c 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2240,6 +2240,7 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
 {
 	int nr_start = *nr;
 	struct dev_pagemap *pgmap = NULL;
+	int ret = 1;
 
 	do {
 		struct page *page = pfn_to_page(pfn);
@@ -2247,12 +2248,14 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
 		pgmap = get_dev_pagemap(pfn, pgmap);
 		if (unlikely(!pgmap)) {
 			undo_dev_pagemap(nr, nr_start, flags, pages);
+			ret = 0;
 			break;
 		}
 		SetPageReferenced(page);
 		pages[*nr] = page;
 		if (unlikely(!try_grab_page(page, flags))) {
 			undo_dev_pagemap(nr, nr_start, flags, pages);
+			ret = 0;
 			break;
 		}
 		(*nr)++;
@@ -2260,7 +2263,7 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
 	} while (addr += PAGE_SIZE, addr != end);
 
 	put_dev_pagemap(pgmap);
-	return 1;
+	return ret;
 }
 
 static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,