Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jordan Crouse , Rob Clark , David Airlie , Johan Hovold , Rob Herring Subject: [PATCH 4.14 32/55] drm/msm: fix OF child-node lookup Date: Thu, 6 Dec 2018 15:39:06 +0100 Message-Id: <20181206143003.451824388@linuxfoundation.org> In-Reply-To: <20181206143001.749982936@linuxfoundation.org> References: <20181206143001.749982936@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold 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 --- drivers/gpu/drm/msm/adreno/adreno_device.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- 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(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; @@ -245,6 +244,8 @@ static int adreno_get_legacy_pwrlevels(s dev_pm_opp_add(dev, val, 0); } + of_node_put(node); + return 0; }