Messages in this thread Patch in this message | | | Date | Mon, 3 Oct 2022 11:10:29 +0300 | From | Matti Vaittinen <> | Subject | [PATCH v3 01/10] iio: adxl367: Fix unsafe buffer attributes |
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The devm_iio_kfifo_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 <mazziesaccount@gmail.com> Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
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v2 => v3: Split change to own patch for simpler fix backporting. --- drivers/iio/accel/adxl367.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/accel/adxl367.c b/drivers/iio/accel/adxl367.c index 47feb375b70b..7c7d78040793 100644 --- a/drivers/iio/accel/adxl367.c +++ b/drivers/iio/accel/adxl367.c @@ -1185,17 +1185,30 @@ static ssize_t adxl367_get_fifo_watermark(struct device *dev, return sysfs_emit(buf, "%d\n", fifo_watermark); } -static IIO_CONST_ATTR(hwfifo_watermark_min, "1"); -static IIO_CONST_ATTR(hwfifo_watermark_max, - __stringify(ADXL367_FIFO_MAX_WATERMARK)); +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(ADXL367_FIFO_MAX_WATERMARK)); +} + +static IIO_DEVICE_ATTR_RO(hwfifo_watermark_min, 0); +static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0); static IIO_DEVICE_ATTR(hwfifo_watermark, 0444, adxl367_get_fifo_watermark, NULL, 0); static IIO_DEVICE_ATTR(hwfifo_enabled, 0444, adxl367_get_fifo_enabled, NULL, 0); static const struct attribute *adxl367_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, -- 2.37.3
-- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =] [unhandled content-type:application/pgp-signature] | |