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* [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe()
@ 2021-04-09  1:58 wangyingjie55
  2021-04-09 16:41 ` Ira Weiny
  0 siblings, 1 reply; 6+ messages in thread
From: wangyingjie55 @ 2021-04-09  1:58 UTC (permalink / raw)
  To: dan.j.williams, vishal.l.verma, dave.jiang, ira.weiny, linux-nvdimm
  Cc: wangyingjie55, linux-kernel

From: Yingjie Wang <wangyingjie55@126.com>

In nd_dax_probe(), 'nd_dax' is allocated by nd_dax_alloc().
nd_dax_alloc() 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.

Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
Signed-off-by: Yingjie Wang <wangyingjie55@126.com>
---
 drivers/nvdimm/dax_devs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 99965077bac4..b1426ac03f01 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -106,6 +106,8 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
 
 	nvdimm_bus_lock(&ndns->dev);
 	nd_dax = nd_dax_alloc(nd_region);
+	if (!nd_dax)
+		return -ENOMEM;
 	nd_pfn = &nd_dax->nd_pfn;
 	dax_dev = nd_pfn_devinit(nd_pfn, ndns);
 	nvdimm_bus_unlock(&ndns->dev);
-- 
2.7.4
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* Re: [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe()
  2021-04-09  1:58 [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe() wangyingjie55
@ 2021-04-09 16:41 ` Ira Weiny
  0 siblings, 0 replies; 6+ messages in thread
From: Ira Weiny @ 2021-04-09 16:41 UTC (permalink / raw)
  To: wangyingjie55; +Cc: linux-nvdimm, linux-kernel

On Thu, Apr 08, 2021 at 06:58:26PM -0700, wangyingjie55@126.com wrote:
> From: Yingjie Wang <wangyingjie55@126.com>
> 
> In nd_dax_probe(), 'nd_dax' is allocated by nd_dax_alloc().
> nd_dax_alloc() may fail and return NULL, so we should better check

Avoid the use of 'we'.

> it's return value to avoid a NULL pointer dereference
> a bit later in the code.

How about:

"nd_dax_alloc() may fail and return NULL.  Check for NULL before attempting to
use nd_dax to avoid a NULL pointer dereference."

> 
> Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
> Signed-off-by: Yingjie Wang <wangyingjie55@126.com>

The code looks good though.

Ira

> ---
>  drivers/nvdimm/dax_devs.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
> index 99965077bac4..b1426ac03f01 100644
> --- a/drivers/nvdimm/dax_devs.c
> +++ b/drivers/nvdimm/dax_devs.c
> @@ -106,6 +106,8 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
>  
>  	nvdimm_bus_lock(&ndns->dev);
>  	nd_dax = nd_dax_alloc(nd_region);
> +	if (!nd_dax)
> +		return -ENOMEM;
>  	nd_pfn = &nd_dax->nd_pfn;
>  	dax_dev = nd_pfn_devinit(nd_pfn, ndns);
>  	nvdimm_bus_unlock(&ndns->dev);
> -- 
> 2.7.4
> 
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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe()
  2021-04-10  0:33 wangyingjie55
@ 2021-04-10  4:54 ` Dan Williams
  0 siblings, 0 replies; 6+ messages in thread
From: Dan Williams @ 2021-04-10  4:54 UTC (permalink / raw)
  To: wangyingjie55; +Cc: linux-nvdimm, Linux Kernel Mailing List

On Fri, Apr 9, 2021 at 5:33 PM <wangyingjie55@126.com> wrote:
>
> From: Yingjie Wang <wangyingjie55@126.com>
>
> In nd_dax_probe(), nd_dax_alloc() may fail and return NULL.
> Check for NULL before attempting to
> use nd_dax to avoid a NULL pointer dereference.
>
> Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
> Signed-off-by: Yingjie Wang <wangyingjie55@126.com>
> ---
>  drivers/nvdimm/dax_devs.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
> index 99965077bac4..b1426ac03f01 100644
> --- a/drivers/nvdimm/dax_devs.c
> +++ b/drivers/nvdimm/dax_devs.c
> @@ -106,6 +106,8 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
>
>         nvdimm_bus_lock(&ndns->dev);

hmmm...

>         nd_dax = nd_dax_alloc(nd_region);
> +       if (!nd_dax)
> +               return -ENOMEM;

Can you spot the bug this introduces? See the hint above.

>         nd_pfn = &nd_dax->nd_pfn;
>         dax_dev = nd_pfn_devinit(nd_pfn, ndns);
>         nvdimm_bus_unlock(&ndns->dev);
> --
> 2.7.4
>
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^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe()
@ 2021-04-10  0:33 wangyingjie55
  2021-04-10  4:54 ` Dan Williams
  0 siblings, 1 reply; 6+ messages in thread
From: wangyingjie55 @ 2021-04-10  0:33 UTC (permalink / raw)
  To: dan.j.williams, vishal.l.verma, dave.jiang, ira.weiny, linux-nvdimm
  Cc: wangyingjie55, linux-kernel

From: Yingjie Wang <wangyingjie55@126.com>

In nd_dax_probe(), nd_dax_alloc() may fail and return NULL.
Check for NULL before attempting to
use nd_dax to avoid a NULL pointer dereference.

Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
Signed-off-by: Yingjie Wang <wangyingjie55@126.com>
---
 drivers/nvdimm/dax_devs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 99965077bac4..b1426ac03f01 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -106,6 +106,8 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
 
 	nvdimm_bus_lock(&ndns->dev);
 	nd_dax = nd_dax_alloc(nd_region);
+	if (!nd_dax)
+		return -ENOMEM;
 	nd_pfn = &nd_dax->nd_pfn;
 	dax_dev = nd_pfn_devinit(nd_pfn, ndns);
 	nvdimm_bus_unlock(&ndns->dev);
-- 
2.7.4
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^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe()
@ 2021-03-17  9:36 wangyingjie55
  0 siblings, 0 replies; 6+ messages in thread
From: wangyingjie55 @ 2021-03-17  9:36 UTC (permalink / raw)
  To: dan.j.williams, vishal.l.verma, dave.jiang, ira.weiny
  Cc: wangyingjie55, linux-nvdimm, linux-kernel

From: Yingjie Wang <wangyingjie55@126.com>

In nd_dax_probe(), 'nd_dax' is allocated by nd_dax_alloc().
nd_dax_alloc() 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.

Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
Signed-off-by: Yingjie Wang <wangyingjie55@126.com>
---
 drivers/nvdimm/dax_devs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 99965077bac4..b1426ac03f01 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -106,6 +106,8 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
 
 	nvdimm_bus_lock(&ndns->dev);
 	nd_dax = nd_dax_alloc(nd_region);
+	if (!nd_dax)
+		return -ENOMEM;
 	nd_pfn = &nd_dax->nd_pfn;
 	dax_dev = nd_pfn_devinit(nd_pfn, ndns);
 	nvdimm_bus_unlock(&ndns->dev);
-- 
2.7.4
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* [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe()
@ 2021-03-17  9:32 wangyingjie55
  0 siblings, 0 replies; 6+ messages in thread
From: wangyingjie55 @ 2021-03-17  9:32 UTC (permalink / raw)
  To: dan.j.williams, vishal.l.verma, dave.jiang, ira.weiny
  Cc: wangyingjie55, linux-nvdimm, linux-kernel

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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From: Yingjie Wang <wangyingjie55@126.com>

In nd_dax_probe(), 'nd_dax' is allocated by nd_dax_alloc().
nd_dax_alloc() 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.

Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
Signed-off-by: Yingjie Wang <wangyingjie55@126.com>
---
 drivers/nvdimm/dax_devs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 99965077bac4..b1426ac03f01 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -106,6 +106,8 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
 
 	nvdimm_bus_lock(&ndns->dev);
 	nd_dax = nd_dax_alloc(nd_region);
+	if (!nd_dax)
+		return -ENOMEM;
 	nd_pfn = &nd_dax->nd_pfn;
 	dax_dev = nd_pfn_devinit(nd_pfn, ndns);
 	nvdimm_bus_unlock(&ndns->dev);
-- 
2.7.4

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end of thread, other threads:[~2021-04-10  4:56 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-09  1:58 [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe() wangyingjie55
2021-04-09 16:41 ` Ira Weiny
  -- strict thread matches above, loose matches on Subject: below --
2021-04-10  0:33 wangyingjie55
2021-04-10  4:54 ` Dan Williams
2021-03-17  9:36 wangyingjie55
2021-03-17  9:32 wangyingjie55

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