linux-kernel - [PATCH v2 1/5] mm/memory-failure: unlock_page before put

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]

Date:	Fri, 31 Jul 2015 06:46:12 +0000
From:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	Andi Kleen <andi@...stfloor.org>, Dean Nelson <dnelson@...hat.com>,
	"Tony Luck" <tony.luck@...el.com>,
	"Kirill A. Shutemov" <kirill@...temov.name>,
	"Hugh Dickins" <hughd@...gle.com>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"Naoya Horiguchi" <nao.horiguchi@...il.com>,
	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
Subject: [PATCH v2 1/5] mm/memory-failure: unlock_page before put_page

In "just unpoisoned" path, we do put_page and then unlock_page, which is a
wrong order and causes "freeing locked page" bug. So let's fix it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@...jp.nec.com>
---
 mm/memory-failure.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git v4.2-rc4.orig/mm/memory-failure.c v4.2-rc4/mm/memory-failure.c
index c53543d89282..04d677048af7 100644
--- v4.2-rc4.orig/mm/memory-failure.c
+++ v4.2-rc4/mm/memory-failure.c
@@ -1209,9 +1209,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 	if (!PageHWPoison(p)) {
 		printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
 		atomic_long_sub(nr_pages, &num_poisoned_pages);
+		unlock_page(hpage);
 		put_page(hpage);
-		res = 0;
-		goto out;
+		return 0;
 	}
 	if (hwpoison_filter(p)) {
 		if (TestClearPageHWPoison(p))
-- 
2.4.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/