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")
Johan
------------------ original commit in Linus's tree ------------------
From f9a7082327e26f54067a49cac2316d31e0cc8ba7 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
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
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index da1363a0c54d..93d70f4a2154 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -633,8 +633,7 @@ 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;
@@ -655,6 +654,8 @@ static int adreno_get_legacy_pwrlevels(struct device *dev) dev_pm_opp_add(dev, val, 0); }
- of_node_put(node);
- return 0;
}