From a10a0f385ab8af08ddb762ac3eca11e1b6d1fe69 Mon Sep 17 00:00:00 2001 From: Matti Vaittinen Date: Mon, 3 Oct 2022 11:11:12 +0300 Subject: [PATCH] iio: bmc150-accel-core: Fix unsafe buffer attributes The iio_triggered_buffer_setup_ext() was changed by commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") to silently expect that all attributes given in buffer_attrs array are device-attributes. This expectation was not forced by the API - and some drivers did register attributes created by IIO_CONST_ATTR(). The added attribute "wrapping" does not copy the pointer to stored string constant and when the sysfs file is read the kernel will access to invalid location. Change the IIO_CONST_ATTRs from the driver to IIO_DEVICE_ATTR in order to prevent the invalid memory access. Signed-off-by: Matti Vaittinen Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") Link: https://lore.kernel.org/r/cf8a56658fc38db8bed64f456d898f5ad5a2814f.1664782676.git.mazziesaccount@gmail.com Signed-off-by: Jonathan Cameron --- drivers/iio/accel/bmc150-accel-core.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c index 57e8a8350cd16..92f8b139acce9 100644 --- a/drivers/iio/accel/bmc150-accel-core.c +++ b/drivers/iio/accel/bmc150-accel-core.c @@ -925,17 +925,30 @@ static const struct iio_chan_spec_ext_info bmc150_accel_ext_info[] = { { } }; -static IIO_CONST_ATTR(hwfifo_watermark_min, "1"); -static IIO_CONST_ATTR(hwfifo_watermark_max, - __stringify(BMC150_ACCEL_FIFO_LENGTH)); +static ssize_t hwfifo_watermark_min_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", "1"); +} + +static ssize_t hwfifo_watermark_max_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", __stringify(BMC150_ACCEL_FIFO_LENGTH)); +} + +static IIO_DEVICE_ATTR_RO(hwfifo_watermark_min, 0); +static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0); static IIO_DEVICE_ATTR(hwfifo_enabled, S_IRUGO, bmc150_accel_get_fifo_state, NULL, 0); static IIO_DEVICE_ATTR(hwfifo_watermark, S_IRUGO, bmc150_accel_get_fifo_watermark, NULL, 0); static const struct attribute *bmc150_accel_fifo_attributes[] = { - &iio_const_attr_hwfifo_watermark_min.dev_attr.attr, - &iio_const_attr_hwfifo_watermark_max.dev_attr.attr, + &iio_dev_attr_hwfifo_watermark_min.dev_attr.attr, + &iio_dev_attr_hwfifo_watermark_max.dev_attr.attr, &iio_dev_attr_hwfifo_watermark.dev_attr.attr, &iio_dev_attr_hwfifo_enabled.dev_attr.attr, NULL, -- 2.30.2