linux-kernel - [PATCH] [71/99] PM: Free memory bitmaps if opening /dev/snapshot fails

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: <20110727214910.91BE82403FF@tassilo.jf.intel.com>
Date:	Wed, 27 Jul 2011 14:49:10 -0700 (PDT)
From:	Andi Kleen <andi@...stfloor.org>
To:	mkubecek@...e.cz, rjw@...k.pl, gregkh@...e.de, ak@...ux.intel.com,
	linux-kernel@...r.kernel.org, stable@...nel.org,
	tim.bird@...sony.com
Subject: [PATCH] [71/99] PM: Free memory bitmaps if opening /dev/snapshot fails

2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Michal Kubecek <mkubecek@...e.cz>

commit 8440f4b19494467883f8541b7aa28c7bbf6ac92b upstream.

When opening /dev/snapshot device, snapshot_open() creates memory
bitmaps which are freed in snapshot_release(). But if any of the
callbacks called by pm_notifier_call_chain() returns NOTIFY_BAD, open()
fails, snapshot_release() is never called and bitmaps are not freed.
Next attempt to open /dev/snapshot then triggers BUG_ON() check in
create_basic_memory_bitmaps(). This happens e.g. when vmwatchdog module
is active on s390x.

Signed-off-by: Michal Kubecek <mkubecek@...e.cz>
Signed-off-by: Rafael J. Wysocki <rjw@...k.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
Signed-off-by: Andi Kleen <ak@...ux.intel.com>

---
 kernel/power/user.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6.35.y/kernel/power/user.c
===================================================================
--- linux-2.6.35.y.orig/kernel/power/user.c
+++ linux-2.6.35.y/kernel/power/user.c
@@ -113,8 +113,10 @@ static int snapshot_open(struct inode *i
 		if (error)
 			pm_notifier_call_chain(PM_POST_RESTORE);
 	}
-	if (error)
+	if (error) {
+		free_basic_memory_bitmaps();
 		atomic_inc(&snapshot_device_available);
+	}
 	data->frozen = 0;
 	data->ready = 0;
 	data->platform_support = 0;
--
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/