diff options
| author | Tzung-Bi Shih | 2023-08-29 11:06:22 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-10-25 12:03:09 +0200 |
| commit | 3b02dbd1cd54d6184b904ea17ee664ba15186a77 (patch) | |
| tree | f69c626701704cc5d553936f8b17333df996a0a8 /drivers/iio | |
| parent | 7bca0af538a49dacb1470f233be0676bdc09605b (diff) | |
iio: cros_ec: fix an use-after-free in cros_ec_sensors_push_data()
[ Upstream commit 7771c8c80d62ad065637ef74ed2962983f6c5f6d ]
cros_ec_sensors_push_data() reads `indio_dev->active_scan_mask` and
calls iio_push_to_buffers_with_timestamp() without making sure the
`indio_dev` stays in buffer mode. There is a race if `indio_dev` exits
buffer mode right before cros_ec_sensors_push_data() accesses them.
An use-after-free on `indio_dev->active_scan_mask` was observed. The
call trace:
[...]
_find_next_bit
cros_ec_sensors_push_data
cros_ec_sensorhub_event
blocking_notifier_call_chain
cros_ec_irq_thread
It was caused by a race condition: one thread just freed
`active_scan_mask` at [1]; while another thread tried to access the
memory at [2].
Fix it by calling iio_device_claim_buffer_mode() to ensure the
`indio_dev` can't exit buffer mode during cros_ec_sensors_push_data().
[1]: https://elixir.bootlin.com/linux/v6.5/source/drivers/iio/industrialio-buffer.c#L1189
[2]: https://elixir.bootlin.com/linux/v6.5/source/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c#L198
Cc: stable@vger.kernel.org
Fixes: aa984f1ba4a4 ("iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230829030622.1571852-1-tzungbi@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c index d98f7e4d202c..1ddce991fb3f 100644 --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c @@ -190,8 +190,11 @@ int cros_ec_sensors_push_data(struct iio_dev *indio_dev, /* * Ignore samples if the buffer is not set: it is needed if the ODR is * set but the buffer is not enabled yet. + * + * Note: iio_device_claim_buffer_mode() returns -EBUSY if the buffer + * is not enabled. */ - if (!iio_buffer_enabled(indio_dev)) + if (iio_device_claim_buffer_mode(indio_dev) < 0) return 0; out = (s16 *)st->samples; @@ -210,6 +213,7 @@ int cros_ec_sensors_push_data(struct iio_dev *indio_dev, iio_push_to_buffers_with_timestamp(indio_dev, st->samples, timestamp + delta); + iio_device_release_buffer_mode(indio_dev); return 0; } EXPORT_SYMBOL_GPL(cros_ec_sensors_push_data); |