FAILED: patch "[PATCH] iio:imu:bmi160: Fix alignment and data leak issues" failed to apply to 5.4-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7b6b51234df6cd8b04fe736b0b89c25612d896b8 Mon Sep 17 00:00:00 2001
From: Jonathan Cameron <[email protected]>
Date: Sun, 20 Sep 2020 12:27:39 +0100
Subject: [PATCH] iio:imu:bmi160: Fix alignment and data leak issues
One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses an array of smaller elements on the stack. As Lars also noted this anti pattern can involve a leak of data to userspace and that indeed can happen here. We close both issues by moving to a suitable array in the iio_priv() data with alignment explicitly requested. This data is allocated with kzalloc() so no data can leak apart from previous readings.
In this driver, depending on which channels are enabled, the timestamp can be in a number of locations. Hence we cannot use a structure to specify the data layout without it being misleading.
drivers/iio/imu/bmi160/bmi160.h +7 -0
@@ -10,6 +10,13 @@ struct bmi160_data {struct iio_trigger *trig;struct regulator_bulk_data supplies[2 ];struct iio_mount_matrix orientation; +/* +* Ensure natural alignment for timestamp if present. +* Max length needed: 2 * 3 channels + 4 bytes padding + 8 byte ts. +* If fewer channels are enabled, less space may be needed, as +* long as the timestamp is still aligned to 8 bytes. +*/ +__le16 buf[12 ]__aligned(8) ; };extern const struct regmap_config bmi160_regmap_config;
drivers/iio/imu/bmi160/bmi160_core.c +2 -4
@@ -427,8 +427,6 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p)struct iio_poll_func *pf = p;struct iio_dev *indio_dev = pf->indio_dev;struct bmi160_data *data =iio_priv (indio_dev); -__le16 buf[12 ]; -/* 2 sens x 3 axis x __le16 + 2 x __le16 pad + 4 x __le16 tstamp */ int i, ret, j =0 , base =BMI160_REG_DATA_MAGN_XOUT_L ;__le16 sample;
@@ -438,10 +436,10 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p) &sample, sizeof(sample));if (ret) goto done; - buf[j++] = sample; + data->buf[j++] = sample; } -iio_push_to_buffers_with_timestamp (indio_dev, buf, pf->timestamp); +iio_push_to_buffers_with_timestamp (indio_dev, data->buf, pf->timestamp); done:iio_trigger_notify_done (indio_dev->trig);return IRQ_HANDLED ;
Sudip Mukherjee
Reviewed-by Alexandru ArdeleanHi Greg,
Quoted 5 lines · On Mon, Dec 28, 2020 at 12:14:30PM +0100, [email protected] wrote:
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Here is the backport.
--
Regards
Sudip
From 95e5471b49cff9a070f68365e2ae6c558203ab07 Mon Sep 17 00:00:00 2001
From: Jonathan Cameron <[email protected]>
Date: Sun, 20 Sep 2020 12:27:39 +0100
Subject: [PATCH] iio:imu:bmi160: Fix alignment and data leak issues
commit 7b6b51234df6cd8b04fe736b0b89c25612d896b8 upstream
One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses an array of smaller elements on the stack. As Lars also noted this anti pattern can involve a leak of data to userspace and that indeed can happen here. We close both issues by moving to a suitable array in the iio_priv() data with alignment explicitly requested. This data is allocated with kzalloc() so no data can leak apart from previous readings.
In this driver, depending on which channels are enabled, the timestamp can be in a number of locations. Hence we cannot use a structure to specify the data layout without it being misleading.
--- drivers/iio/imu/bmi160/bmi160.h | 7 +++++++ drivers/iio/imu/bmi160/bmi160_core.c | 6 ++---- 2 files changed, 9 insertions(+), 4 deletions(-)
drivers/iio/imu/bmi160/bmi160.h +7 -0
@@ -7,6 +7,13 @@struct bmi160_data {struct regmap *regmap;struct iio_trigger *trig; +/* +* Ensure natural alignment for timestamp if present. +* Max length needed: 2 * 3 channels + 4 bytes padding + 8 byte ts. +* If fewer channels are enabled, less space may be needed, as +* long as the timestamp is still aligned to 8 bytes. +*/ +__le16 buf[12 ]__aligned(8) ; };extern const struct regmap_config bmi160_regmap_config;
drivers/iio/imu/bmi160/bmi160_core.c +2 -4
@@ -411,8 +411,6 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p)struct iio_poll_func *pf = p;struct iio_dev *indio_dev = pf->indio_dev;struct bmi160_data *data =iio_priv (indio_dev); -__le16 buf[12 ]; -/* 2 sens x 3 axis x __le16 + 2 x __le16 pad + 4 x __le16 tstamp */ int i, ret, j =0 , base =BMI160_REG_DATA_MAGN_XOUT_L ;__le16 sample;
@@ -422,10 +420,10 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p) &sample, sizeof(sample));if (ret) goto done; - buf[j++] = sample; + data->buf[j++] = sample; } -iio_push_to_buffers_with_timestamp (indio_dev, buf, pf->timestamp); +iio_push_to_buffers_with_timestamp (indio_dev, data->buf, pf->timestamp); done:iio_trigger_notify_done (indio_dev->trig);return IRQ_HANDLED ;
Signature · 1 line
2.11.0