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[90.63.244.31]) by smtp.gmail.com with ESMTPSA id x18sm5580002wrw.19.2021.06.17.07.58.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 17 Jun 2021 07:58:20 -0700 (PDT) Subject: Re: [PATCH] drm/meson: fix potential NULL pointer exception in meson_drv_unbind() To: Jiajun Cao Cc: yuanxzhang@fudan.edu.cn, Xin Tan , David Airlie , Daniel Vetter , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , dri-devel@lists.freedesktop.org, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20210617070737.50171-1-jjcao20@fudan.edu.cn> From: Neil Armstrong Organization: Baylibre Message-ID: <0c367cae-9bad-d53a-01db-3d2dd801965b@baylibre.com> Date: Thu, 17 Jun 2021 16:58:20 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210617070737.50171-1-jjcao20@fudan.edu.cn> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210617_075824_147262_005E224B X-CRM114-Status: GOOD ( 18.13 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org Hi, On 17/06/2021 09:07, Jiajun Cao wrote: > Fix a potential NULL pointer exception when meson_drv_unbind() > attempts to operate on the driver_data priv which may be NULL. > Add a null pointer check on the priv struct to avoid the NULL > pointer dereference after calling dev_get_drvdata(), just like > the null pointer checks done on the struct priv in the function > meson_drv_shutdown(), meson_drv_pm_suspend() and meson_drv_pm_resume(). > > Signed-off-by: Jiajun Cao > Signed-off-by: Xin Tan > --- > drivers/gpu/drm/meson/meson_drv.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c > index 07fcd12dca16..adea6a2b28f5 100644 > --- a/drivers/gpu/drm/meson/meson_drv.c > +++ b/drivers/gpu/drm/meson/meson_drv.c > @@ -380,6 +380,8 @@ static int meson_drv_bind(struct device *dev) > static void meson_drv_unbind(struct device *dev) > { > struct meson_drm *priv = dev_get_drvdata(dev); > + if (!priv) > + return; > struct drm_device *drm = priv->drm; Please move struct drm_device before the if like : struct meson_drm *priv = dev_get_drvdata(dev); struct drm_device *drm; if (!priv) return; drm = priv->drm; > > if (priv->canvas) { > Thanks, Neil _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic