On Thu, Nov 29, 2018 at 09:06:29AM +0100, Greg Kroah-Hartman wrote:

On Tue, Nov 27, 2018 at 07:19:38AM -0800, Johan Hovold wrote:

...

On Mon, Nov 19, 2018 at 03:07:37PM +0100, Greg Kroah-Hartman wrote:

...

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

This one also depends on

36156f9241cb ("of: add helper to lookup compatible child node")

No, still does not apply to 4.14 even with that patch :(

Looks like the function in question was moved by commit 999ae6edc1c1 ("drm/msm/adreno: Move clock parsing to adreno_gpu_init()").

Compile-tested backport below.

Johan

From 8ac9a34ac02928bcc2975fd3da39671fd4d533e7 Mon Sep 17 00:00:00 2001

From: Johan Hovold johan@kernel.org Date: Mon, 27 Aug 2018 10:21:47 +0200 Subject: [PATCH] drm/msm: fix OF child-node lookup

commit f9a7082327e26f54067a49cac2316d31e0cc8ba7 upstream.

Use the new of_get_compatible_child() helper to lookup the legacy pwrlevels child node instead of using of_find_compatible_node(), which searches the entire tree from a given start node and thus can return an unrelated (i.e. non-child) node.

This also addresses a potential use-after-free (e.g. after probe deferral) as the tree-wide helper drops a reference to its first argument (i.e. the probed device's node).

While at it, also fix the related child-node reference leak.

Fixes: e2af8b6b0ca1 ("drm/msm: gpu: Use OPP tables if we can") Cc: stable stable@vger.kernel.org # 4.12 Cc: Jordan Crouse jcrouse@codeaurora.org Cc: Rob Clark robdclark@gmail.com Cc: David Airlie airlied@linux.ie Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Rob Herring robh@kernel.org [ johan: backport to 4.14 ] Signed-off-by: Johan Hovold johan@kernel.org --- drivers/gpu/drm/msm/adreno/adreno_device.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c index c75c4df4bc39..2c379774d3f2 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_device.c +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c @@ -223,8 +223,7 @@ static int adreno_get_legacy_pwrlevels(struct device *dev) struct device_node *child, *node; int ret;

- node = of_find_compatible_node(dev->of_node, NULL, - "qcom,gpu-pwrlevels"); + node = of_get_compatible_child(dev->of_node, "qcom,gpu-pwrlevels"); if (!node) { dev_err(dev, "Could not find the GPU powerlevels\n"); return -ENXIO; @@ -245,6 +244,8 @@ static int adreno_get_legacy_pwrlevels(struct device *dev) dev_pm_opp_add(dev, val, 0); }

+ of_node_put(node); + return 0; }