4.18-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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; }