* [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion()
@ 2023-08-28 16:55 Zhang Shurong
2023-08-28 17:28 ` Laurent Pinchart
0 siblings, 1 reply; 5+ messages in thread
From: Zhang Shurong @ 2023-08-28 16:55 UTC (permalink / raw)
To: victor.liu
Cc: andrzej.hajda, neil.armstrong, rfoss, Laurent.pinchart, jonas,
jernej.skrabec, airlied, daniel, shawnguo, s.hauer, kernel,
festevam, linux-imx, dri-devel, linux-arm-kernel, linux-kernel,
Zhang Shurong
of_match_device() may fail and returns a NULL pointer.
Fix this by checking the return value of of_match_device().
Fixes: 3818715f62b4 ("drm/bridge: imx: Add LDB support for i.MX8qxp")
Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
---
drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c
index 7984da9c0a35..d272f35c8eac 100644
--- a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c
+++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c
@@ -488,6 +488,8 @@ static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb)
* string.
*/
match = of_match_device(dev->driver->of_match_table, dev);
+ if (!match)
+ return -ENODEV;
if (!of_device_is_compatible(companion, match->compatible)) {
DRM_DEV_ERROR(dev, "companion LDB is incompatible\n");
ret = -ENXIO;
--
2.30.2
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^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion() 2023-08-28 16:55 [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion() Zhang Shurong @ 2023-08-28 17:28 ` Laurent Pinchart 2023-08-28 18:01 ` Zhang Shurong 0 siblings, 1 reply; 5+ messages in thread From: Laurent Pinchart @ 2023-08-28 17:28 UTC (permalink / raw) To: Zhang Shurong Cc: victor.liu, andrzej.hajda, neil.armstrong, rfoss, jonas, jernej.skrabec, airlied, daniel, shawnguo, s.hauer, kernel, festevam, linux-imx, dri-devel, linux-arm-kernel, linux-kernel Hi Zhang, Thank you for the patch. On Tue, Aug 29, 2023 at 12:55:01AM +0800, Zhang Shurong wrote: > of_match_device() may fail and returns a NULL pointer. How can it return a NULL pointer here ? > Fix this by checking the return value of of_match_device(). > > Fixes: 3818715f62b4 ("drm/bridge: imx: Add LDB support for i.MX8qxp") > Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com> > --- > drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > index 7984da9c0a35..d272f35c8eac 100644 > --- a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > @@ -488,6 +488,8 @@ static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb) > * string. > */ > match = of_match_device(dev->driver->of_match_table, dev); > + if (!match) > + return -ENODEV; > if (!of_device_is_compatible(companion, match->compatible)) { > DRM_DEV_ERROR(dev, "companion LDB is incompatible\n"); > ret = -ENXIO; -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion() 2023-08-28 17:28 ` Laurent Pinchart @ 2023-08-28 18:01 ` Zhang Shurong 2023-08-28 18:37 ` Laurent Pinchart 0 siblings, 1 reply; 5+ messages in thread From: Zhang Shurong @ 2023-08-28 18:01 UTC (permalink / raw) To: Laurent Pinchart Cc: victor.liu, andrzej.hajda, neil.armstrong, rfoss, jonas, jernej.skrabec, airlied, daniel, shawnguo, s.hauer, kernel, festevam, linux-imx, dri-devel, linux-arm-kernel, linux-kernel 在 2023年8月29日星期二 CST 上午1:28:22，Laurent Pinchart 写道： > Hi Zhang, > > Thank you for the patch. > > On Tue, Aug 29, 2023 at 12:55:01AM +0800, Zhang Shurong wrote: > > of_match_device() may fail and returns a NULL pointer. > > How can it return a NULL pointer here ? > > > Fix this by checking the return value of of_match_device(). > > > > Fixes: 3818715f62b4 ("drm/bridge: imx: Add LDB support for i.MX8qxp") > > Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com> > > --- > > > > drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c index > > 7984da9c0a35..d272f35c8eac 100644 > > --- a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > @@ -488,6 +488,8 @@ static int imx8qxp_ldb_parse_dt_companion(struct > > imx8qxp_ldb *imx8qxp_ldb)> > > * string. > > */ > > > > match = of_match_device(dev->driver->of_match_table, dev); > > > > + if (!match) > > + return -ENODEV; > > > > if (!of_device_is_compatible(companion, match->compatible)) { > > > > DRM_DEV_ERROR(dev, "companion LDB is incompatible\n"); > > ret = -ENXIO; I think we can make it happen by designing the platform device in a way that its name aligns with that of the driver. In such a scenario, when the driver is probed, the of_match_device function will return null. You can verify this functionality by reviewing the following function: static int platform_match(struct device *dev, struct device_driver *drv) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion() 2023-08-28 18:01 ` Zhang Shurong @ 2023-08-28 18:37 ` Laurent Pinchart 2023-08-29 2:28 ` Ying Liu 0 siblings, 1 reply; 5+ messages in thread From: Laurent Pinchart @ 2023-08-28 18:37 UTC (permalink / raw) To: Zhang Shurong Cc: victor.liu, andrzej.hajda, neil.armstrong, rfoss, jonas, jernej.skrabec, airlied, daniel, shawnguo, s.hauer, kernel, festevam, linux-imx, dri-devel, linux-arm-kernel, linux-kernel On Tue, Aug 29, 2023 at 02:01:25AM +0800, Zhang Shurong wrote: > 在 2023年8月29日星期二 CST 上午1:28:22，Laurent Pinchart 写道： > > Hi Zhang, > > > > Thank you for the patch. > > > > On Tue, Aug 29, 2023 at 12:55:01AM +0800, Zhang Shurong wrote: > > > of_match_device() may fail and returns a NULL pointer. > > > > How can it return a NULL pointer here ? > > > > > Fix this by checking the return value of of_match_device(). > > > > > > Fixes: 3818715f62b4 ("drm/bridge: imx: Add LDB support for i.MX8qxp") > > > Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com> > > > --- > > > > > > drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > > b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c index > > > 7984da9c0a35..d272f35c8eac 100644 > > > --- a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > > @@ -488,6 +488,8 @@ static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb) > > > * string. > > > */ > > > match = of_match_device(dev->driver->of_match_table, dev); > > > + if (!match) > > > + return -ENODEV; > > > if (!of_device_is_compatible(companion, match->compatible)) { > > > DRM_DEV_ERROR(dev, "companion LDB is incompatible\n"); > > > ret = -ENXIO; > > I think we can make it happen by designing the platform device in a way that > its name aligns with that of the driver. In such a scenario, when the driver > is probed, the of_match_device function will return null. You can verify this > functionality by reviewing the following function: > > static int platform_match(struct device *dev, struct device_driver *drv) This particular device is found in OF-based systems only, and only instantiated through DT. You can create a platform_device manually that may match this driver, but that would be a made-up situation, not something that can happen in practice. -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion() 2023-08-28 18:37 ` Laurent Pinchart @ 2023-08-29 2:28 ` Ying Liu 0 siblings, 0 replies; 5+ messages in thread From: Ying Liu @ 2023-08-29 2:28 UTC (permalink / raw) To: Laurent Pinchart, Zhang Shurong Cc: andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, jonas@kwiboo.se, jernej.skrabec@gmail.com, airlied@gmail.com, daniel@ffwll.ch, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, dl-linux-imx, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org On Tuesday, August 29, 2023 2:38 AM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > On Tue, Aug 29, 2023 at 02:01:25AM +0800, Zhang Shurong wrote: > > 在 2023年8月29日星期二 CST 上午1:28:22，Laurent Pinchart 写道： > > > Hi Zhang, > > > > > > Thank you for the patch. > > > > > > On Tue, Aug 29, 2023 at 12:55:01AM +0800, Zhang Shurong wrote: > > > > of_match_device() may fail and returns a NULL pointer. > > > > > > How can it return a NULL pointer here ? > > > > > > > Fix this by checking the return value of of_match_device(). > > > > > > > > Fixes: 3818715f62b4 ("drm/bridge: imx: Add LDB support for i.MX8qxp") > > > > Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com> > > > > --- > > > > > > > > drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > > > b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c index > > > > 7984da9c0a35..d272f35c8eac 100644 > > > > --- a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > > > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > > > > @@ -488,6 +488,8 @@ static int > imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb) > > > > * string. > > > > */ > > > > match = of_match_device(dev->driver->of_match_table, dev); > > > > + if (!match) > > > > + return -ENODEV; > > > > if (!of_device_is_compatible(companion, match->compatible)) { > > > > DRM_DEV_ERROR(dev, "companion LDB is incompatible\n"); > > > > ret = -ENXIO; > > > > I think we can make it happen by designing the platform device in a way > that > > its name aligns with that of the driver. In such a scenario, when the driver > > is probed, the of_match_device function will return null. You can verify this > > functionality by reviewing the following function: > > > > static int platform_match(struct device *dev, struct device_driver *drv) > > This particular device is found in OF-based systems only, and only > instantiated through DT. You can create a platform_device manually that > may match this driver, but that would be a made-up situation, not > something that can happen in practice. > I agree with Laurent. Regards, Liu Ying _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-08-29 2:29 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2023-08-28 16:55 [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion() Zhang Shurong 2023-08-28 17:28 ` Laurent Pinchart 2023-08-28 18:01 ` Zhang Shurong 2023-08-28 18:37 ` Laurent Pinchart 2023-08-29 2:28 ` Ying Liu
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