From 26da8040eccc6c6b0e415e9a3baf72fd39eb2fdc Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Thu, 13 May 2021 15:07:42 +0300 Subject: [PATCH] iio: adc: ad7124: Fix potential overflow due to non sequential channel numbers commit f2a772c51206b0c3f262e4f6a3812c89a650191b upstream. Channel numbering must start at 0 and then not have any holes, or it is possible to overflow the available storage. Note this bug was introduced as part of a fix to ensure we didn't rely on the ordering of child nodes. So we need to support arbitrary ordering but they all need to be there somewhere. Note I hit this when using qemu to test the rest of this series. Arguably this isn't the best fix, but it is probably the most minimal option for backporting etc. Alexandru's sign-off is here because he carried this patch in a larger set that Jonathan then applied. Fixes: d7857e4ee1ba6 ("iio: adc: ad7124: Fix DT channel configuration") Reviewed-by: Alexandru Ardelean Signed-off-by: Jonathan Cameron Signed-off-by: Alexandru Ardelean Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/ad7124.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c index c0d0870a29ffb..9c2401c5848ec 100644 --- a/drivers/iio/adc/ad7124.c +++ b/drivers/iio/adc/ad7124.c @@ -616,6 +616,13 @@ static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev, if (ret) goto err; + if (channel >= indio_dev->num_channels) { + dev_err(indio_dev->dev.parent, + "Channel index >= number of channels\n"); + ret = -EINVAL; + goto err; + } + ret = of_property_read_u32_array(child, "diff-channels", ain, 2); if (ret)