Commit a10a0f38 authored by Matti Vaittinen's avatar Matti Vaittinen Committed by Jonathan Cameron
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iio: bmc150-accel-core: Fix unsafe buffer attributes 



The iio_triggered_buffer_setup_ext() was changed by
commit 15097c7a ("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: default avatarMatti Vaittinen <mazziesaccount@gmail.com>
Fixes: 15097c7a ("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: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 5e23b33d

drivers/iio/accel/bmc150-accel-core.c

+18 −5
Original line number Diff line number Diff line
@@ -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,