linux-kernel - [PATCH 6/6] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge

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

Message-Id: <20210104065843.5658-6-songmuchun@bytedance.com>
Date:   Mon,  4 Jan 2021 14:58:43 +0800
From:   Muchun Song <songmuchun@...edance.com>
To:     mike.kravetz@...cle.com, akpm@...ux-foundation.org
Cc:     hillf.zj@...baba-inc.com, n-horiguchi@...jp.nec.com,
        ak@...ux.intel.com, yongjun_wei@...ndmicro.com.cn, mhocko@...e.cz,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Muchun Song <songmuchun@...edance.com>
Subject: [PATCH 6/6] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active

The page_huge_active() can be called from scan_movable_pages() which
do not hold a reference count to the HugeTLB page. So when we call
page_huge_active() from scan_movable_pages(), the HugeTLB page can
be freed parallel. Then we will trigger a BUG_ON which is in the
page_huge_active() when CONFIG_DEBUG_VM is enabled. Just remove the
VM_BUG_ON_PAGE.

Fixes: 7e1f049efb86 ("mm: hugetlb: cleanup using paeg_huge_active()")
Signed-off-by: Muchun Song <songmuchun@...edance.com>
---
 mm/hugetlb.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5c2f64f53177..4c8631114e88 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1360,7 +1360,6 @@ struct hstate *size_to_hstate(unsigned long size)
  */
 bool page_huge_active(struct page *page)
 {
-	VM_BUG_ON_PAGE(!PageHuge(page), page);
 	return PageHead(page) && PagePrivate(&page[1]);
 }
 
-- 
2.11.0