This is a note to let you know that I've just added the patch titled iio: inkern: only release the device node when done with it to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iio-inkern-only-release-the-device-node-when-done-wi.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e35762549db53aebf6c83ef47965005558a828c9 Author: Nuno Sá <nuno.sa@xxxxxxxxxx> Date: Fri Jul 15 14:28:49 2022 +0200 iio: inkern: only release the device node when done with it [ Upstream commit 79c3e84874c7d14f04ad58313b64955a0d2e9437 ] 'of_node_put()' can potentially release the memory pointed to by 'iiospec.np' which would leave us with an invalid pointer (and we would still pass it in 'of_xlate()'). Note that it is not guaranteed for the of_node lifespan to be attached to the device (to which is attached) lifespan so that there is (even though very unlikely) the possibility for the node to be freed while the device is still around. Thus, as there are indeed some of_xlate users which do access the node, a race is indeed possible. As such, we can only release the node after we are done with it. Fixes: 17d82b47a215d ("iio: Add OF support") Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220715122903.332535-2-nuno.sa@xxxxxxxxxx Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index b5966365d769..30a8ecb692f8 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -148,9 +148,10 @@ static int __of_iio_channel_get(struct iio_channel *channel, idev = bus_find_device(&iio_bus_type, NULL, iiospec.np, iio_dev_node_match); - of_node_put(iiospec.np); - if (idev == NULL) + if (idev == NULL) { + of_node_put(iiospec.np); return -EPROBE_DEFER; + } indio_dev = dev_to_iio_dev(idev); channel->indio_dev = indio_dev; @@ -158,6 +159,7 @@ static int __of_iio_channel_get(struct iio_channel *channel, index = indio_dev->info->of_xlate(indio_dev, &iiospec); else index = __of_iio_simple_xlate(indio_dev, &iiospec); + of_node_put(iiospec.np); if (index < 0) goto err_put; channel->channel = &indio_dev->channels[index];