[PATCH stable 4.9 16/21] media: dvb_frontend: be sure to init dvb_frontend_handle_ioctl() return code

From: Florian Fainelli <f.fainelli@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org,
	Mauro Carvalho Chehab <mchehab@s-opensource.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Michael Krufky <mkrufky@linuxtv.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Shuah Khan <shuah@kernel.org>,
	Jaedon Shin <jaedon.shin@gmail.com>,
	Colin Ian King <colin.king@canonical.com>,
	Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>,
	Satendra Singh Thakur <satendra.t@samsung.com>,
	linux-media@vger.kernel.org (open list:MEDIA INPUT
	INFRASTRUCTURE (V4L/DVB)),
	linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and
	infrastructure))
Subject: [PATCH stable 4.9 16/21] media: dvb_frontend: be sure to init dvb_frontend_handle_ioctl() return code
Date: Fri,  5 Jun 2020 09:25:13 -0700	[thread overview]
Message-ID: <20200605162518.28099-17-florian.fainelli@broadcom.com> (raw)
In-Reply-To: <20200605162518.28099-1-florian.fainelli@broadcom.com>

From: Mauro Carvalho Chehab <mchehab@s-opensource.com>

commit a9cb97c3e628902e37583d8a40bb28cf76522cf1 upstream

As smatch warned:
	drivers/media/dvb-core/dvb_frontend.c:2468 dvb_frontend_handle_ioctl() error: uninitialized symbol 'err'.

The ioctl handler actually got a regression here: before changeset
d73dcf0cdb95 ("media: dvb_frontend: cleanup ioctl handling logic"),
the code used to return -EOPNOTSUPP if an ioctl handler was not
implemented on a driver. After the change, it may return a random
value.

Fixes: d73dcf0cdb95 ("media: dvb_frontend: cleanup ioctl handling logic")

Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Tested-by: Daniel Scheller <d.scheller@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/media/dvb-core/dvb_frontend.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
index a9ae9e509205..6f9ee78a1870 100644
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -2113,7 +2113,7 @@ static int dvb_frontend_handle_ioctl(struct file *file,
 	struct dvb_frontend *fe = dvbdev->priv;
 	struct dvb_frontend_private *fepriv = fe->frontend_priv;
 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-	int i, err;
+	int i, err = -EOPNOTSUPP;
 
 	dev_dbg(fe->dvb->device, "%s:\n", __func__);
 
@@ -2148,6 +2148,7 @@ static int dvb_frontend_handle_ioctl(struct file *file,
 			}
 		}
 		kfree(tvp);
+		err = 0;
 		break;
 	}
 	case FE_GET_PROPERTY: {
@@ -2198,6 +2199,7 @@ static int dvb_frontend_handle_ioctl(struct file *file,
 			return -EFAULT;
 		}
 		kfree(tvp);
+		err = 0;
 		break;
 	}
 
-- 
2.17.1

