linux-kernel - [PATCH 3.14 01/34] mm: frontswap: invalidate expired data on a dup-store failure

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20141214201803.834650102@linuxfoundation.org>
Date:	Sun, 14 Dec 2014 12:20:39 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Weijie Yang <weijie.yang@...sung.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Seth Jennings <sjennings@...iantweb.net>,
	Dan Streetman <ddstreet@...e.org>,
	Minchan Kim <minchan@...nel.org>, Bob Liu <bob.liu@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [PATCH 3.14 01/34] mm: frontswap: invalidate expired data on a dup-store failure

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Weijie Yang <weijie.yang@...sung.com>

commit fb993fa1a2f669215fa03a09eed7848f2663e336 upstream.

If a frontswap dup-store failed, it should invalidate the expired page
in the backend, or it could trigger some data corruption issue.
Such as:
 1. use zswap as the frontswap backend with writeback feature
 2. store a swap page(version_1) to entry A, success
 3. dup-store a newer page(version_2) to the same entry A, fail
 4. use __swap_writepage() write version_2 page to swapfile, success
 5. zswap do shrink, writeback version_1 page to swapfile
 6. version_2 page is overwrited by version_1, data corrupt.

This patch fixes this issue by invalidating expired data immediately
when meet a dup-store failure.

Signed-off-by: Weijie Yang <weijie.yang@...sung.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Cc: Seth Jennings <sjennings@...iantweb.net>
Cc: Dan Streetman <ddstreet@...e.org>
Cc: Minchan Kim <minchan@...nel.org>
Cc: Bob Liu <bob.liu@...cle.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 mm/frontswap.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -244,8 +244,10 @@ int __frontswap_store(struct page *page)
 		  the (older) page from frontswap
 		 */
 		inc_frontswap_failed_stores();
-		if (dup)
+		if (dup) {
 			__frontswap_clear(sis, offset);
+			frontswap_ops->invalidate_page(type, offset);
+		}
 	}
 	if (frontswap_writethrough_enabled)
 		/* report failure so swap also writes to swap device */


--
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/