linux-kernel - [PATCH AUTOSEL 4.19 27/87] media: cec-core: first mark device unregistered, then wake up fhs

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: <20201223022103.2792705-27-sashal@kernel.org>
Date:   Tue, 22 Dec 2020 21:20:03 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Hans Verkuil <hverkuil-cisco@...all.nl>,
        Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
        Sasha Levin <sashal@...nel.org>, linux-media@...r.kernel.org
Subject: [PATCH AUTOSEL 4.19 27/87] media: cec-core: first mark device unregistered, then wake up fhs

From: Hans Verkuil <hverkuil-cisco@...all.nl>

[ Upstream commit e91c255733d9bbb4978a372f44fb5ed689ccdbd1 ]

If a CEC device node is unregistered, then it should be marked as
unregistered before waking up any filehandles that are waiting for
an event.

This ensures that there is no race condition where an application can
call CEC_DQEVENT and have the ioctl return 0 instead of ENODEV.

Signed-off-by: Hans Verkuil <hverkuil-cisco@...all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/media/cec/cec-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/cec/cec-core.c b/drivers/media/cec/cec-core.c
index b278ab90b3871..1cd2f9d4a6045 100644
--- a/drivers/media/cec/cec-core.c
+++ b/drivers/media/cec/cec-core.c
@@ -160,12 +160,12 @@ static void cec_devnode_unregister(struct cec_adapter *adap)
 		mutex_unlock(&devnode->lock);
 		return;
 	}
+	devnode->registered = false;
+	devnode->unregistered = true;
 
 	list_for_each_entry(fh, &devnode->fhs, list)
 		wake_up_interruptible(&fh->wait);
 
-	devnode->registered = false;
-	devnode->unregistered = true;
 	mutex_unlock(&devnode->lock);
 
 	mutex_lock(&adap->lock);
-- 
2.27.0