linux-kernel - [PATCH 4.9 05/72] extcon: Remove potential problem when calling extcon_register

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: <20171119143532.593012804@linuxfoundation.org>
Date:   Sun, 19 Nov 2017 15:38:09 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Chanwoo Choi <cw00.choi@...sung.com>,
        Sasha Levin <alexander.levin@...izon.com>
Subject: [PATCH 4.9 05/72] extcon: Remove potential problem when calling extcon_register_notifier()

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

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

From: Chanwoo Choi <cw00.choi@...sung.com>


[ Upstream commit 01b4c9a1ae07a25d208cad0da7dd288007a22984 ]

This patch removes the potential problem of extcon_register_notifier()
when edev parameter is NULL. When edev is NULL, this function returns
the first extcon device which includes the sepecific external connector
of second paramter. But, it don't guarantee the same operation in all cases.
To remove this confusion and potential problem, this patch fixes it.

Signed-off-by: Chanwoo Choi <cw00.choi@...sung.com>
Signed-off-by: Sasha Levin <alexander.levin@...izon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/extcon/extcon.c |   35 ++++++++---------------------------
 1 file changed, 8 insertions(+), 27 deletions(-)

--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -906,35 +906,16 @@ int extcon_register_notifier(struct extc
 	unsigned long flags;
 	int ret, idx = -EINVAL;
 
-	if (!nb)
+	if (!edev || !nb)
 		return -EINVAL;
 
-	if (edev) {
-		idx = find_cable_index_by_id(edev, id);
-		if (idx < 0)
-			return idx;
-
-		spin_lock_irqsave(&edev->lock, flags);
-		ret = raw_notifier_chain_register(&edev->nh[idx], nb);
-		spin_unlock_irqrestore(&edev->lock, flags);
-	} else {
-		struct extcon_dev *extd;
-
-		mutex_lock(&extcon_dev_list_lock);
-		list_for_each_entry(extd, &extcon_dev_list, entry) {
-			idx = find_cable_index_by_id(extd, id);
-			if (idx >= 0)
-				break;
-		}
-		mutex_unlock(&extcon_dev_list_lock);
-
-		if (idx >= 0) {
-			edev = extd;
-			return extcon_register_notifier(extd, id, nb);
-		} else {
-			ret = -ENODEV;
-		}
-	}
+	idx = find_cable_index_by_id(edev, id);
+	if (idx < 0)
+		return idx;
+
+	spin_lock_irqsave(&edev->lock, flags);
+	ret = raw_notifier_chain_register(&edev->nh[idx], nb);
+	spin_unlock_irqrestore(&edev->lock, flags);
 
 	return ret;
 }