* [PATCH -next] misc: vexpress: Fix potential NULL dereference in vexpress_syscfg_probe() @ 2018-07-11 13:17 Wei Yongjun 2018-07-11 15:41 ` Sudeep Holla 0 siblings, 1 reply; 3+ messages in thread From: Wei Yongjun @ 2018-07-11 13:17 UTC (permalink / raw) To: linux-arm-kernel platform_get_resource() may fail and return NULL, so we should better check it's return value to avoid a NULL pointer dereference a bit later in the code. This is detected by Coccinelle semantic patch. @@ expression pdev, res, n, t, e, e1, e2; @@ res = platform_get_resource(pdev, t, n); + if (!res) + return -EINVAL; ... when != res == NULL e = devm_ioremap(e1, res->start, e2); Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> --- drivers/misc/vexpress-syscfg.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c index 9eea30f..2d72c93 100644 --- a/drivers/misc/vexpress-syscfg.c +++ b/drivers/misc/vexpress-syscfg.c @@ -259,6 +259,8 @@ static int vexpress_syscfg_probe(struct platform_device *pdev) INIT_LIST_HEAD(&syscfg->funcs); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -EINVAL; if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res), pdev->name)) return -EBUSY; ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH -next] misc: vexpress: Fix potential NULL dereference in vexpress_syscfg_probe() 2018-07-11 13:17 [PATCH -next] misc: vexpress: Fix potential NULL dereference in vexpress_syscfg_probe() Wei Yongjun @ 2018-07-11 15:41 ` Sudeep Holla 2018-07-12 9:18 ` Liviu Dudau 0 siblings, 1 reply; 3+ messages in thread From: Sudeep Holla @ 2018-07-11 15:41 UTC (permalink / raw) To: linux-arm-kernel On Wed, Jul 11, 2018 at 01:17:38PM +0000, Wei Yongjun wrote: > platform_get_resource() may fail and return NULL, so we should > better check it's return value to avoid a NULL pointer dereference > a bit later in the code. > > This is detected by Coccinelle semantic patch. > > @@ > expression pdev, res, n, t, e, e1, e2; > @@ > > res = platform_get_resource(pdev, t, n); > + if (!res) > + return -EINVAL; > ... when != res == NULL > e = devm_ioremap(e1, res->start, e2); Instead of adding unnecessary check here, I would go with replacing it with devm_ioremap_resource as it's designed to deal with that (patch inline) Regards, Sudeep -->8 >From a6de466984e657dad24dcbe87e5dde2d21cb8d35 Mon Sep 17 00:00:00 2001 From: Sudeep Holla <sudeep.holla@arm.com> Date: Wed, 11 Jul 2018 16:17:39 +0100 Subject: [PATCH] misc: vexpress/syscfg: Use devm_ioremap_resource() to map memory Instead of checking the return value of platform_get_resource(), we can use devm_ioremap_resource() which has the NULL pointer check and the memory region requesting. devm_ioremap_resource is designed to replace calls to devm_request_mem_region followed by devm_ioremap, so let's use the same. Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- drivers/misc/vexpress-syscfg.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c index 80a6f199077c..6c3591cdf855 100644 --- a/drivers/misc/vexpress-syscfg.c +++ b/drivers/misc/vexpress-syscfg.c @@ -258,13 +258,9 @@ static int vexpress_syscfg_probe(struct platform_device *pdev) INIT_LIST_HEAD(&syscfg->funcs); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!devm_request_mem_region(&pdev->dev, res->start, - resource_size(res), pdev->name)) - return -EBUSY; - - syscfg->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); - if (!syscfg->base) - return -EFAULT; + syscfg->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(syscfg->base)) + return PTR_ERR(syscfg->base); /* Must use dev.parent (MFD), as that's where DT phandle points at... */ bridge = vexpress_config_bridge_register(pdev->dev.parent, -- 2.7.4 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH -next] misc: vexpress: Fix potential NULL dereference in vexpress_syscfg_probe() 2018-07-11 15:41 ` Sudeep Holla @ 2018-07-12 9:18 ` Liviu Dudau 0 siblings, 0 replies; 3+ messages in thread From: Liviu Dudau @ 2018-07-12 9:18 UTC (permalink / raw) To: linux-arm-kernel On Wed, Jul 11, 2018 at 04:41:10PM +0100, Sudeep Holla wrote: > On Wed, Jul 11, 2018 at 01:17:38PM +0000, Wei Yongjun wrote: > > platform_get_resource() may fail and return NULL, so we should > > better check it's return value to avoid a NULL pointer dereference > > a bit later in the code. > > > > This is detected by Coccinelle semantic patch. > > > > @@ > > expression pdev, res, n, t, e, e1, e2; > > @@ > > > > res = platform_get_resource(pdev, t, n); > > + if (!res) > > + return -EINVAL; > > ... when != res == NULL > > e = devm_ioremap(e1, res->start, e2); > > Instead of adding unnecessary check here, I would go with replacing it > with devm_ioremap_resource as it's designed to deal with that (patch inline) > > Regards, > Sudeep > > -->8 > From a6de466984e657dad24dcbe87e5dde2d21cb8d35 Mon Sep 17 00:00:00 2001 > From: Sudeep Holla <sudeep.holla@arm.com> > Date: Wed, 11 Jul 2018 16:17:39 +0100 > Subject: [PATCH] misc: vexpress/syscfg: Use devm_ioremap_resource() to map > memory > > Instead of checking the return value of platform_get_resource(), we can > use devm_ioremap_resource() which has the NULL pointer check and the > memory region requesting. devm_ioremap_resource is designed to replace > calls to devm_request_mem_region followed by devm_ioremap, so let's use > the same. > > Cc: Liviu Dudau <liviu.dudau@arm.com> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Liviu Dudau <liviu.dudau@arm.com> > --- > drivers/misc/vexpress-syscfg.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c > index 80a6f199077c..6c3591cdf855 100644 > --- a/drivers/misc/vexpress-syscfg.c > +++ b/drivers/misc/vexpress-syscfg.c > @@ -258,13 +258,9 @@ static int vexpress_syscfg_probe(struct platform_device *pdev) > INIT_LIST_HEAD(&syscfg->funcs); > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > - if (!devm_request_mem_region(&pdev->dev, res->start, > - resource_size(res), pdev->name)) > - return -EBUSY; > - > - syscfg->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); > - if (!syscfg->base) > - return -EFAULT; > + syscfg->base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(syscfg->base)) > + return PTR_ERR(syscfg->base); > > /* Must use dev.parent (MFD), as that's where DT phandle points at... */ > bridge = vexpress_config_bridge_register(pdev->dev.parent, > -- > 2.7.4 > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ?\_(?)_/? ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-07-12 9:18 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-07-11 13:17 [PATCH -next] misc: vexpress: Fix potential NULL dereference in vexpress_syscfg_probe() Wei Yongjun 2018-07-11 15:41 ` Sudeep Holla 2018-07-12 9:18 ` Liviu Dudau
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