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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, Martin Kelly <mkelly@xevo.com>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Stable@vger.kernel.org,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>
Subject: [PATCH 4.20 06/50] tools: iio: iio_generic_buffer: make num_loops signed
Date:   Wed, 13 Feb 2019 19:38:11 +0100
Message-Id: <20190213183656.291941329@linuxfoundation.org>
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4.20-stable review patch.  If anyone has any objections, please let me know.

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

From: Martin Kelly <mkelly@xevo.com>

commit b119d3bc328e7a9574861ebe0c2110e2776c2de1 upstream.

Currently, num_loops is unsigned, but it's set by strtoll, which returns a
(signed) long long int. This could lead to overflow, and it also makes the
check "num_loops < 0" always be false, since num_loops is unsigned.
Setting num_loops to -1 to loop forever is almost working because num_loops
is getting set to a very high number, but it's technically still incorrect.

Fix this issue by making num_loops signed. This also fixes an error found
by Smatch.

Signed-off-by: Martin Kelly <mkelly@xevo.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 55dda0abcf9d ("tools: iio: iio_generic_buffer: allow continuous looping")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/iio/iio_generic_buffer.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/iio/iio_generic_buffer.c
+++ b/tools/iio/iio_generic_buffer.c
@@ -330,7 +330,7 @@ static const struct option longopts[] =
 
 int main(int argc, char **argv)
 {
-	unsigned long long num_loops = 2;
+	long long num_loops = 2;
 	unsigned long timedelay = 1000000;
 	unsigned long buf_len = 128;