Re: [PATCH 5.15.y] iio: adc: ad7923: Fix buffer overflow for tx_buf and ring_xfer

[Jonathan Cameron]

On Thu,  9 Apr 2026 14:51:47 +0800
Robert Garcia <rob_garcia@xxxxxxx> wrote:

> From: Nuno Sa <nuno.sa@xxxxxxxxxx>
> 
> [ Upstream commit 3a4187ec454e19903fd15f6e1825a4b84e59a4cd ]
> 
> The AD7923 was updated to support devices with 8 channels, but the size
> of tx_buf and ring_xfer was not increased accordingly, leading to a
> potential buffer overflow in ad7923_update_scan_mode().
> 
> Fixes: 851644a60d20 ("iio: adc: ad7923: Add support for the ad7908/ad7918/ad7928")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
> Signed-off-by: Zicheng Qu <quzicheng@xxxxxxxxxx>
> Link: https://patch.msgid.link/20241029134637.2261336-1-quzicheng@xxxxxxxxxx
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> [ Context change fixed. ]
> Signed-off-by: Robert Garcia <rob_garcia@xxxxxxx>

If it's not picked up already, then backporting as here looks fine to me.
Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>

> ---
>  drivers/iio/adc/ad7923.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7923.c b/drivers/iio/adc/ad7923.c
> index b8cc94b7dd80..a8e59fd2dcf3 100644
> --- a/drivers/iio/adc/ad7923.c
> +++ b/drivers/iio/adc/ad7923.c
> @@ -47,7 +47,7 @@
>  
>  struct ad7923_state {
>  	struct spi_device		*spi;
> -	struct spi_transfer		ring_xfer[5];
> +	struct spi_transfer		ring_xfer[9];
>  	struct spi_transfer		scan_single_xfer[2];
>  	struct spi_message		ring_msg;
>  	struct spi_message		scan_single_msg;
> @@ -63,7 +63,7 @@ struct ad7923_state {
>  	 * Length = 8 channels + 4 extra for 8 byte timestamp
>  	 */
>  	__be16				rx_buf[12] ____cacheline_aligned;
> -	__be16				tx_buf[4];
> +	__be16				tx_buf[8];
>  };
>  
>  struct ad7923_chip_info {