linux-kernel - [PATCH 3.8 85/91] [SCSI] enclosure: fix WARN

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: <1388682306-30859-86-git-send-email-kamal@canonical.com>
Date:	Thu,  2 Jan 2014 09:05:00 -0800
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	James Bottomley <JBottomley@...allels.com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.8 85/91] [SCSI] enclosure: fix WARN_ON in dual path device removing

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

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

From: James Bottomley <JBottomley@...allels.com>

commit a1470c7bf3a4676e62e4c0fb204e339399eb5c59 upstream.

Bug report from: wenxiong@...ux.vnet.ibm.com

The issue is happened in dual controller configuration. We got the
sysfs warnings when rmmod the ipr module.

enclosure_unregister() in drivers/msic/enclosure.c, call device_unregister()
for each componment deivce, device_unregister() ->device_del()->kobject_del()
->sysfs_remove_dir(). In sysfs_remove_dir(), set kobj->sd = NULL.

For each componment device,
enclosure_component_release()->enclosure_remove_links()->sysfs_remove_link()
in which checking kobj->sd again, it has been set as NULL when doing
device_unregister. So we saw all these sysfs WARNING.

Tested-by: wenxiong@...ux.vnet.ibm.com
Signed-off-by: James Bottomley <JBottomley@...allels.com>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 drivers/misc/enclosure.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
index 00e5fcac8..cbee842 100644
--- a/drivers/misc/enclosure.c
+++ b/drivers/misc/enclosure.c
@@ -198,6 +198,13 @@ static void enclosure_remove_links(struct enclosure_component *cdev)
 {
 	char name[ENCLOSURE_NAME_SIZE];
 
+	/*
+	 * In odd circumstances, like multipath devices, something else may
+	 * already have removed the links, so check for this condition first.
+	 */
+	if (!cdev->dev->kobj.sd)
+		return;
+
 	enclosure_link_name(cdev, name);
 	sysfs_remove_link(&cdev->dev->kobj, name);
 	sysfs_remove_link(&cdev->cdev.kobj, "device");
-- 
1.8.3.2

--
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/