From: Johan Hovold Date: Mon, 27 Aug 2018 08:21:47 +0000 (+0200) Subject: drm/msm: fix OF child-node lookup X-Git-Tag: v4.14.87~24 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=84ee7f89237f096a6fd2906bb7d909d3ba8a0432;p=platform%2Fkernel%2Flinux-exynos.git 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 # 4.12 Cc: Jordan Crouse Cc: Rob Clark Cc: David Airlie Signed-off-by: Johan Hovold Signed-off-by: Rob Herring [ johan: backport to 4.14 ] Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c index c75c4df..2c37977 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; }