The patch titled
Subject: mm: memory-failure: fix potential page refcnt leak in memory_failure()
has been added to the -mm mm-unstable branch. Its filename is
mm-memory-failure-fix-potential-page-refcnt-leak-in-memory_failure.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory-failure-fix-potential-page-refcnt-leak-in-memory_failure.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm: memory-failure: fix potential page refcnt leak in memory_failure()
Date: Sat, 1 Jul 2023 15:28:37 +0800
put_ref_page() is not called to drop extra refcnt when comes from madvise
in the case pfn is valid but pgmap is NULL leading to page refcnt leak.
Link: https://lkml.kernel.org/r/20230701072837.1994253-1-linmiaohe@xxxxxxxxxx
Fixes: 1e8aaedb182d ("mm,memory_failure: always pin the page in madvise_inject_error")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/mm/memory-failure.c~mm-memory-failure-fix-potential-page-refcnt-leak-in-memory_failure
+++ a/mm/memory-failure.c
@@ -2080,8 +2080,6 @@ static int memory_failure_dev_pagemap(un
{
int rc = -ENXIO;
- put_ref_page(pfn, flags);
-
/* device metadata space is not recoverable */
if (!pgmap_pfn_valid(pgmap, pfn))
goto out;
@@ -2157,6 +2155,7 @@ int memory_failure(unsigned long pfn, in
if (pfn_valid(pfn)) {
pgmap = get_dev_pagemap(pfn, NULL);
+ put_ref_page(pfn, flags);
if (pgmap) {
res = memory_failure_dev_pagemap(pfn, flags,
pgmap);
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-mm_initc-update-obsolete-comment-in-get_pfn_range_for_nid.patch
mm-memory-failure-fix-unexpected-return-value-in-soft_offline_page.patch
mm-memory-failure-fix-potential-page-refcnt-leak-in-memory_failure.patch
