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From:   gregkh@linuxfoundation.org
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ian Abbott <abbotti@mev.co.uk>
Subject: [PATCH 4.9 55/78] staging: comedi: das800: Fix endian problem for AI command data
Date:   Mon, 15 Mar 2021 14:52:18 +0100
Message-Id: <20210315135213.880534562@linuxfoundation.org>
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Ian Abbott <abbotti@mev.co.uk>

commit 459b1e8c8fe97fcba0bd1b623471713dce2c5eaf upstream.

The analog input subdevice supports Comedi asynchronous commands that
use Comedi's 16-bit sample format.  However, the call to
`comedi_buf_write_samples()` is passing the address of a 32-bit integer
variable.  On bigendian machines, this will copy 2 bytes from the wrong
end of the 32-bit value.  Fix it by changing the type of the variable
holding the sample value to `unsigned short`.

Fixes: ad9eb43c93d8 ("staging: comedi: das800: use comedi_buf_write_samples()")
Cc: <stable@vger.kernel.org> # 3.19+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210223143055.257402-6-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/comedi/drivers/das800.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/staging/comedi/drivers/das800.c
+++ b/drivers/staging/comedi/drivers/das800.c
@@ -436,7 +436,7 @@ static irqreturn_t das800_interrupt(int
 	struct comedi_cmd *cmd;
 	unsigned long irq_flags;
 	unsigned int status;
-	unsigned int val;
+	unsigned short val;
 	bool fifo_empty;
 	bool fifo_overflow;
 	int i;