linux-kernel - [PATCH] mm: hugetlb: fix missing put_page in gather_surplus

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 26 Jan 2021 11:10:09 +0800
From:   Muchun Song <songmuchun@...edance.com>
To:     mike.kravetz@...cle.com, akpm@...ux-foundation.org
Cc:     sh_def@....com, linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Muchun Song <songmuchun@...edance.com>, stable@...r.kernel.org
Subject: [PATCH] mm: hugetlb: fix missing put_page in gather_surplus_pages()

The VM_BUG_ON_PAGE avoids the generation of any code, even if that
expression has side-effects when !CONFIG_DEBUG_VM.

Fixes: e5dfacebe4a4 ("mm/hugetlb.c: just use put_page_testzero() instead of page_count()")
Signed-off-by: Muchun Song <songmuchun@...edance.com>
Cc: <stable@...r.kernel.org>
---
 mm/hugetlb.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a6bad1f686c5..082ed643020b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2047,13 +2047,16 @@ static int gather_surplus_pages(struct hstate *h, long delta)
 
 	/* Free the needed pages to the hugetlb pool */
 	list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
+		int zeroed;
+
 		if ((--needed) < 0)
 			break;
 		/*
 		 * This page is now managed by the hugetlb allocator and has
 		 * no users -- drop the buddy allocator's reference.
 		 */
-		VM_BUG_ON_PAGE(!put_page_testzero(page), page);
+		zeroed = put_page_testzero(page);
+		VM_BUG_ON_PAGE(!zeroed, page);
 		enqueue_huge_page(h, page);
 	}
 free:
-- 
2.11.0