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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tom Rix <trix@redhat.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 025/117] media: tw5864: check status of tw5864_frameinterval_get
Date:   Mon,  9 Nov 2020 13:54:11 +0100
Message-Id: <20201109125026.849551537@linuxfoundation.org>
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From: Tom Rix <trix@redhat.com>

[ Upstream commit 780d815dcc9b34d93ae69385a8465c38d423ff0f ]

clang static analysis reports this problem

tw5864-video.c:773:32: warning: The left expression of the compound
  assignment is an uninitialized value.
  The computed value will also be garbage
        fintv->stepwise.max.numerator *= std_max_fps;
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^

stepwise.max is set with frameinterval, which comes from

	ret = tw5864_frameinterval_get(input, &frameinterval);
	fintv->stepwise.step = frameinterval;
	fintv->stepwise.min = frameinterval;
	fintv->stepwise.max = frameinterval;
	fintv->stepwise.max.numerator *= std_max_fps;

When tw5864_frameinterval_get() fails, frameinterval is not
set. So check the status and fix another similar problem.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/pci/tw5864/tw5864-video.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/media/pci/tw5864/tw5864-video.c b/drivers/media/pci/tw5864/tw5864-video.c
index 27ff6e0d98453..023ff9ebde5e7 100644
--- a/drivers/media/pci/tw5864/tw5864-video.c
+++ b/drivers/media/pci/tw5864/tw5864-video.c
@@ -767,6 +767,9 @@ static int tw5864_enum_frameintervals(struct file *file, void *priv,
 	fintv->type = V4L2_FRMIVAL_TYPE_STEPWISE;
 
 	ret = tw5864_frameinterval_get(input, &frameinterval);
+	if (ret)
+		return ret;
+
 	fintv->stepwise.step = frameinterval;
 	fintv->stepwise.min = frameinterval;
 	fintv->stepwise.max = frameinterval;
@@ -785,6 +788,9 @@ static int tw5864_g_parm(struct file *file, void *priv,
 	cp->capability = V4L2_CAP_TIMEPERFRAME;
 
 	ret = tw5864_frameinterval_get(input, &cp->timeperframe);
+	if (ret)
+		return ret;
+
 	cp->timeperframe.numerator *= input->frame_interval;
 	cp->capturemode = 0;
 	cp->readbuffers = 2;
-- 
2.27.0