patch "iio: buffer-dmaengine: fix releasing dma channel on error" added to char-misc-linus

patch "iio: buffer-dmaengine: fix releasing dma channel on error" added to char-misc-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    iio: buffer-dmaengine: fix releasing dma channel on error

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From 84c65d8008764a8fb4e627ff02de01ec4245f2c4 Mon Sep 17 00:00:00 2001
From: David Lechner <dlechner@baylibre.com>
Date: Tue, 23 Jul 2024 11:32:21 -0500
Subject: iio: buffer-dmaengine: fix releasing dma channel on error

If dma_get_slave_caps() fails, we need to release the dma channel before
returning an error to avoid leaking the channel.

Fixes: 2d6ca60f3284 ("iio: Add a DMAengine framework based buffer")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20240723-iio-fix-dmaengine-free-on-error-v1-1-2c7cbc9b92ff@baylibre.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/buffer/industrialio-buffer-dmaengine.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 12aa1412dfa0..426cc614587a 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -237,7 +237,7 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
 
 	ret = dma_get_slave_caps(chan, &caps);
 	if (ret < 0)
-		goto err_free;
+		goto err_release;
 
 	/* Needs to be aligned to the maximum of the minimums */
 	if (caps.src_addr_widths)
@@ -263,6 +263,8 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
 
 	return &dmaengine_buffer->queue.buffer;
 
+err_release:
+	dma_release_channel(chan);
 err_free:
 	kfree(dmaengine_buffer);
 	return ERR_PTR(ret);
-- 
2.46.0