From 64ead55b5d167128b0b314dc0dfb98123eb2d897 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nuno=20S=C3=A1?= Date: Fri, 15 Jul 2022 14:28:49 +0200 Subject: [PATCH] iio: inkern: only release the device node when done with it MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ 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 Link: https://lore.kernel.org/r/20220715122903.332535-2-nuno.sa@analog.com Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/inkern.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index 218cf4567ab5..13be4c8d7fd3 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -139,9 +139,10 @@ 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; @@ -149,6 +150,7 @@ 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];