Re: [PATCH] Mtd: nand - Fix possible NULL derefrence.

[Boris Brezillon]

Hi Shailendra,

Marek and I already reviewed this patch, and you're resending it
without any of the comments addressed. Is this a mistake?

On Mon, 30 Jan 2017 10:29:17 +0530
Shailendra Verma  wrote:

> of_match_device could return NULL, and so can cause a NULL
> pointer dereference later.
> 
> Signed-off-by: Shailendra Verma 
> ---
>  drivers/mtd/nand/mxc_nand.c  |4 
>  drivers/mtd/nand/vf610_nfc.c |4 
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index d7f724b..ca1b8ad 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
> *host)
>   if (!np)
>   return 1;
>  
> + if (!of_id) {
> + dev_err(host->dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   host->devtype_data = of_id->data;
>  
>   return 0;
> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> index 3ad514c..0e09c11 100644
> --- a/drivers/mtd/nand/vf610_nfc.c
> +++ b/drivers/mtd/nand/vf610_nfc.c
> @@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
>   }
>  
>   of_id = of_match_device(vf610_nfc_dt_ids, >dev);
> + if (!of_id) {
> + dev_err(>dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   nfc->variant = (enum vf610_nfc_variant)of_id->data;
>  
>   for_each_available_child_of_node(nfc->dev->of_node, child) {

Re: [PATCH] Mtd: nand - Fix possible NULL derefrence.

[Boris Brezillon]

Hi Shailendra,

Marek and I already reviewed this patch, and you're resending it
without any of the comments addressed. Is this a mistake?

On Mon, 30 Jan 2017 10:29:17 +0530
Shailendra Verma  wrote:

> of_match_device could return NULL, and so can cause a NULL
> pointer dereference later.
> 
> Signed-off-by: Shailendra Verma 
> ---
>  drivers/mtd/nand/mxc_nand.c  |4 
>  drivers/mtd/nand/vf610_nfc.c |4 
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index d7f724b..ca1b8ad 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
> *host)
>   if (!np)
>   return 1;
>  
> + if (!of_id) {
> + dev_err(host->dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   host->devtype_data = of_id->data;
>  
>   return 0;
> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> index 3ad514c..0e09c11 100644
> --- a/drivers/mtd/nand/vf610_nfc.c
> +++ b/drivers/mtd/nand/vf610_nfc.c
> @@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
>   }
>  
>   of_id = of_match_device(vf610_nfc_dt_ids, >dev);
> + if (!of_id) {
> + dev_err(>dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   nfc->variant = (enum vf610_nfc_variant)of_id->data;
>  
>   for_each_available_child_of_node(nfc->dev->of_node, child) {

[PATCH] Mtd: nand - Fix possible NULL derefrence.

[Shailendra Verma]

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma 
---
 drivers/mtd/nand/mxc_nand.c  |4 
 drivers/mtd/nand/vf610_nfc.c |4 
 2 files changed, 8 insertions(+)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d7f724b..ca1b8ad 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
*host)
if (!np)
return 1;
 
+   if (!of_id) {
+   dev_err(host->dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
host->devtype_data = of_id->data;
 
return 0;
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 3ad514c..0e09c11 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
}
 
of_id = of_match_device(vf610_nfc_dt_ids, >dev);
+   if (!of_id) {
+   dev_err(>dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
nfc->variant = (enum vf610_nfc_variant)of_id->data;
 
for_each_available_child_of_node(nfc->dev->of_node, child) {
-- 
1.7.9.5

[PATCH] Mtd: nand - Fix possible NULL derefrence.

[Shailendra Verma]

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma 
---
 drivers/mtd/nand/mxc_nand.c  |4 
 drivers/mtd/nand/vf610_nfc.c |4 
 2 files changed, 8 insertions(+)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d7f724b..ca1b8ad 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
*host)
if (!np)
return 1;
 
+   if (!of_id) {
+   dev_err(host->dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
host->devtype_data = of_id->data;
 
return 0;
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 3ad514c..0e09c11 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
}
 
of_id = of_match_device(vf610_nfc_dt_ids, >dev);
+   if (!of_id) {
+   dev_err(>dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
nfc->variant = (enum vf610_nfc_variant)of_id->data;
 
for_each_available_child_of_node(nfc->dev->of_node, child) {
-- 
1.7.9.5

[PATCH] Mtd: nand - Fix possible NULL derefrence.

[Shailendra Verma]

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma 
---
 drivers/mtd/nand/mxc_nand.c  |4 
 drivers/mtd/nand/vf610_nfc.c |4 
 2 files changed, 8 insertions(+)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d7f724b..ca1b8ad 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
*host)
if (!np)
return 1;
 
+   if (!of_id) {
+   dev_err(host->dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
host->devtype_data = of_id->data;
 
return 0;
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 3ad514c..0e09c11 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
}
 
of_id = of_match_device(vf610_nfc_dt_ids, >dev);
+   if (!of_id) {
+   dev_err(>dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
nfc->variant = (enum vf610_nfc_variant)of_id->data;
 
for_each_available_child_of_node(nfc->dev->of_node, child) {
-- 
1.7.9.5

[PATCH] Mtd: nand - Fix possible NULL derefrence.

[Shailendra Verma]

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma 
---
 drivers/mtd/nand/mxc_nand.c  |4 
 drivers/mtd/nand/vf610_nfc.c |4 
 2 files changed, 8 insertions(+)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d7f724b..ca1b8ad 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
*host)
if (!np)
return 1;
 
+   if (!of_id) {
+   dev_err(host->dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
host->devtype_data = of_id->data;
 
return 0;
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 3ad514c..0e09c11 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
}
 
of_id = of_match_device(vf610_nfc_dt_ids, >dev);
+   if (!of_id) {
+   dev_err(>dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
nfc->variant = (enum vf610_nfc_variant)of_id->data;
 
for_each_available_child_of_node(nfc->dev->of_node, child) {
-- 
1.7.9.5

Re: [PATCH] Mtd: nand - Fix possible NULL derefrence.

[Boris Brezillon]

On Fri, 27 Jan 2017 13:24:18 +0100
Marek Vasut  wrote:

> On 01/27/2017 12:29 PM, Shailendra Verma wrote:
> > of_match_device could return NULL, and so can cause a NULL
> > pointer dereference later.
> > 

That's a purely hypothetical bug since the core already matched
against one of the compatible in the of_match table to decide to attach
the device to this driver. Having of_match_device() return NULL here
means something went seriously wrong (memory corruption ?).

This being said, I'm not strongly opposed to this patch. Just a minor
comment below.

Thanks,

Boris

> > Signed-off-by: Shailendra Verma   
> 
> Nice find, but can you split this into two patches ? And the prefix is
> 'mtd' without capital letter.
> 
> Thanks
> 
> > ---
> >  drivers/mtd/nand/mxc_nand.c  |4 
> >  drivers/mtd/nand/vf610_nfc.c |4 
> >  2 files changed, 8 insertions(+)
> > 
> > diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> > index d7f724b..ca1b8ad 100644
> > --- a/drivers/mtd/nand/mxc_nand.c
> > +++ b/drivers/mtd/nand/mxc_nand.c
> > @@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct 
> > mxc_nand_host *host)
> > if (!np)
> > return 1;
> >  
> > +   if (!of_id) {
> > +   dev_err(host->dev, "Error: No device match found\n");
> > +   return -ENODEV;
> > +   }

Add an empty line here.

> > host->devtype_data = of_id->data;
> >  
> > return 0;
> > diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> > index 3ad514c..0e09c11 100644
> > --- a/drivers/mtd/nand/vf610_nfc.c
> > +++ b/drivers/mtd/nand/vf610_nfc.c
> > @@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device 
> > *pdev)
> > }
> >  
> > of_id = of_match_device(vf610_nfc_dt_ids, >dev);
> > +   if (!of_id) {
> > +   dev_err(>dev, "Error: No device match found\n");
> > +   return -ENODEV;
> > +   }

Ditto.

> > nfc->variant = (enum vf610_nfc_variant)of_id->data;
> >  
> > for_each_available_child_of_node(nfc->dev->of_node, child) {
> >   
> 
> 

Re: [PATCH] Mtd: nand - Fix possible NULL derefrence.

[Boris Brezillon]

On Fri, 27 Jan 2017 13:24:18 +0100
Marek Vasut  wrote:

> On 01/27/2017 12:29 PM, Shailendra Verma wrote:
> > of_match_device could return NULL, and so can cause a NULL
> > pointer dereference later.
> > 

That's a purely hypothetical bug since the core already matched
against one of the compatible in the of_match table to decide to attach
the device to this driver. Having of_match_device() return NULL here
means something went seriously wrong (memory corruption ?).

This being said, I'm not strongly opposed to this patch. Just a minor
comment below.

Thanks,

Boris

> > Signed-off-by: Shailendra Verma   
> 
> Nice find, but can you split this into two patches ? And the prefix is
> 'mtd' without capital letter.
> 
> Thanks
> 
> > ---
> >  drivers/mtd/nand/mxc_nand.c  |4 
> >  drivers/mtd/nand/vf610_nfc.c |4 
> >  2 files changed, 8 insertions(+)
> > 
> > diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> > index d7f724b..ca1b8ad 100644
> > --- a/drivers/mtd/nand/mxc_nand.c
> > +++ b/drivers/mtd/nand/mxc_nand.c
> > @@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct 
> > mxc_nand_host *host)
> > if (!np)
> > return 1;
> >  
> > +   if (!of_id) {
> > +   dev_err(host->dev, "Error: No device match found\n");
> > +   return -ENODEV;
> > +   }

Add an empty line here.

> > host->devtype_data = of_id->data;
> >  
> > return 0;
> > diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> > index 3ad514c..0e09c11 100644
> > --- a/drivers/mtd/nand/vf610_nfc.c
> > +++ b/drivers/mtd/nand/vf610_nfc.c
> > @@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device 
> > *pdev)
> > }
> >  
> > of_id = of_match_device(vf610_nfc_dt_ids, >dev);
> > +   if (!of_id) {
> > +   dev_err(>dev, "Error: No device match found\n");
> > +   return -ENODEV;
> > +   }

Ditto.

> > nfc->variant = (enum vf610_nfc_variant)of_id->data;
> >  
> > for_each_available_child_of_node(nfc->dev->of_node, child) {
> >   
> 
> 

Re: [PATCH] Mtd: nand - Fix possible NULL derefrence.

[Marek Vasut]

On 01/27/2017 12:29 PM, Shailendra Verma wrote:
> of_match_device could return NULL, and so can cause a NULL
> pointer dereference later.
> 
> Signed-off-by: Shailendra Verma 

Nice find, but can you split this into two patches ? And the prefix is
'mtd' without capital letter.

Thanks

> ---
>  drivers/mtd/nand/mxc_nand.c  |4 
>  drivers/mtd/nand/vf610_nfc.c |4 
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index d7f724b..ca1b8ad 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
> *host)
>   if (!np)
>   return 1;
>  
> + if (!of_id) {
> + dev_err(host->dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   host->devtype_data = of_id->data;
>  
>   return 0;
> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> index 3ad514c..0e09c11 100644
> --- a/drivers/mtd/nand/vf610_nfc.c
> +++ b/drivers/mtd/nand/vf610_nfc.c
> @@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
>   }
>  
>   of_id = of_match_device(vf610_nfc_dt_ids, >dev);
> + if (!of_id) {
> + dev_err(>dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   nfc->variant = (enum vf610_nfc_variant)of_id->data;
>  
>   for_each_available_child_of_node(nfc->dev->of_node, child) {
> 


-- 
Best regards,
Marek Vasut

Re: [PATCH] Mtd: nand - Fix possible NULL derefrence.

[Marek Vasut]

On 01/27/2017 12:29 PM, Shailendra Verma wrote:
> of_match_device could return NULL, and so can cause a NULL
> pointer dereference later.
> 
> Signed-off-by: Shailendra Verma 

Nice find, but can you split this into two patches ? And the prefix is
'mtd' without capital letter.

Thanks

> ---
>  drivers/mtd/nand/mxc_nand.c  |4 
>  drivers/mtd/nand/vf610_nfc.c |4 
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index d7f724b..ca1b8ad 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
> *host)
>   if (!np)
>   return 1;
>  
> + if (!of_id) {
> + dev_err(host->dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   host->devtype_data = of_id->data;
>  
>   return 0;
> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
> index 3ad514c..0e09c11 100644
> --- a/drivers/mtd/nand/vf610_nfc.c
> +++ b/drivers/mtd/nand/vf610_nfc.c
> @@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
>   }
>  
>   of_id = of_match_device(vf610_nfc_dt_ids, >dev);
> + if (!of_id) {
> + dev_err(>dev, "Error: No device match found\n");
> + return -ENODEV;
> + }
>   nfc->variant = (enum vf610_nfc_variant)of_id->data;
>  
>   for_each_available_child_of_node(nfc->dev->of_node, child) {
> 


-- 
Best regards,
Marek Vasut

[PATCH] Mtd: nand - Fix possible NULL derefrence.

[Shailendra Verma]

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma 
---
 drivers/mtd/nand/mxc_nand.c  |4 
 drivers/mtd/nand/vf610_nfc.c |4 
 2 files changed, 8 insertions(+)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d7f724b..ca1b8ad 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
*host)
if (!np)
return 1;
 
+   if (!of_id) {
+   dev_err(host->dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
host->devtype_data = of_id->data;
 
return 0;
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 3ad514c..0e09c11 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
}
 
of_id = of_match_device(vf610_nfc_dt_ids, >dev);
+   if (!of_id) {
+   dev_err(>dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
nfc->variant = (enum vf610_nfc_variant)of_id->data;
 
for_each_available_child_of_node(nfc->dev->of_node, child) {
-- 
1.7.9.5

[PATCH] Mtd: nand - Fix possible NULL derefrence.

[Shailendra Verma]

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma 
---
 drivers/mtd/nand/mxc_nand.c  |4 
 drivers/mtd/nand/vf610_nfc.c |4 
 2 files changed, 8 insertions(+)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d7f724b..ca1b8ad 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1596,6 +1596,10 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host 
*host)
if (!np)
return 1;
 
+   if (!of_id) {
+   dev_err(host->dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
host->devtype_data = of_id->data;
 
return 0;
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 3ad514c..0e09c11 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -674,6 +674,10 @@ static int vf610_nfc_probe(struct platform_device *pdev)
}
 
of_id = of_match_device(vf610_nfc_dt_ids, >dev);
+   if (!of_id) {
+   dev_err(>dev, "Error: No device match found\n");
+   return -ENODEV;
+   }
nfc->variant = (enum vf610_nfc_variant)of_id->data;
 
for_each_available_child_of_node(nfc->dev->of_node, child) {
-- 
1.7.9.5