diff options
| author | David Lechner | 2023-10-31 16:05:19 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2024-01-01 12:39:01 +0000 |
| commit | 01bc94b581921a3a104d346bbb02e9f459d3a939 (patch) | |
| tree | b8e1de336c2ac9f97628e68ba68649435150968b | |
| parent | c508a99fbc2138052b2f479959455a60886f6c2f (diff) | |
iio: triggered-buffer: prevent possible freeing of wrong buffer
commit bce61476dc82f114e24e9c2e11fb064781ec563c upstream.
Commit ee708e6baacd ("iio: buffer: introduce support for attaching more
IIO buffers") introduced support for multiple buffers per indio_dev but
left indio_dev->buffer for a few legacy use cases.
In the case of the triggered buffer, iio_triggered_buffer_cleanup()
still assumes that indio_dev->buffer points to the buffer allocated by
iio_triggered_buffer_setup_ext(). However, since
iio_triggered_buffer_setup_ext() now calls iio_device_attach_buffer()
to attach the buffer, indio_dev->buffer will only point to the buffer
allocated by iio_device_attach_buffer() if it the first buffer attached.
This adds a check to make sure that no other buffer has been attached
yet to ensure that indio_dev->buffer will be assigned when
iio_device_attach_buffer() is called.
As per discussion in the review thread, we may want to deal with multiple
triggers per device, but this is a fix for the issue in the meantime and
any such support would be unlikely to be suitable for a backport.
Fixes: ee708e6baacd ("iio: buffer: introduce support for attaching more IIO buffers")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Acked-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20231031210521.1661552-1-dlechner@baylibre.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/iio/buffer/industrialio-triggered-buffer.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/iio/buffer/industrialio-triggered-buffer.c b/drivers/iio/buffer/industrialio-triggered-buffer.c index 8d4fc97d1005..2b7873e8a959 100644 --- a/drivers/iio/buffer/industrialio-triggered-buffer.c +++ b/drivers/iio/buffer/industrialio-triggered-buffer.c @@ -46,6 +46,16 @@ int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev, struct iio_buffer *buffer; int ret; + /* + * iio_triggered_buffer_cleanup() assumes that the buffer allocated here + * is assigned to indio_dev->buffer but this is only the case if this + * function is the first caller to iio_device_attach_buffer(). If + * indio_dev->buffer is already set then we can't proceed otherwise the + * cleanup function will try to free a buffer that was not allocated here. + */ + if (indio_dev->buffer) + return -EADDRINUSE; + buffer = iio_kfifo_allocate(); if (!buffer) { ret = -ENOMEM; |