4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Johan Hovold <johan@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx> # 4.12
Cc: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -477,8 +477,7 @@ static int adreno_get_legacy_pwrlevels(s
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;
@@ -499,6 +498,8 @@ static int adreno_get_legacy_pwrlevels(s
dev_pm_opp_add(dev, val, 0);
}
+ of_node_put(node);
+
return 0;
}
