If we fail to allocate propname buffer, we need to drop the reference
count we just took. Because the pinctrl_dt_free_maps() includes the
droping operation, here we call it directly.
Fixes: 91d5c5060ee2 ("pinctrl: devicetree: fix null pointer dereferencing in pinctrl_dt_to_map")
Suggested-by: Dan Carpenter <[email protected]>
Signed-off-by: Zeng Heng <[email protected]>
---
drivers/pinctrl/devicetree.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index df1efc2e5202..6a94ecd6a8de 100644
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -220,14 +220,16 @@ int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
for (state = 0; ; state++) {
/* Retrieve the pinctrl-* property */
propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
- if (!propname)
- return -ENOMEM;
+ if (!propname) {
+ ret = -ENOMEM;
+ goto err;
+ }
prop = of_find_property(np, propname, &size);
kfree(propname);
if (!prop) {
if (state == 0) {
- of_node_put(np);
- return -ENODEV;
+ ret = -ENODEV;
+ goto err;
}
break;
}
--
2.25.1
On Mon, Apr 15, 2024 at 06:53:28PM +0800, Zeng Heng wrote:
> If we fail to allocate propname buffer, we need to drop the reference
> count we just took. Because the pinctrl_dt_free_maps() includes the
> droping operation, here we call it directly.
>
> Fixes: 91d5c5060ee2 ("pinctrl: devicetree: fix null pointer dereferencing in pinctrl_dt_to_map")
> Suggested-by: Dan Carpenter <[email protected]>
> Signed-off-by: Zeng Heng <[email protected]>
> ---
Thanks!
Reviewed-by: Dan Carpenter <[email protected]>
regards,
dan carpenter
> … Because the pinctrl_dt_free_maps() includes the
> droping operation, here we call it directly.
I find this change description improvable.
* How do you think about to avoid a typo?
* Would another imperative wording be more desirable?
Regards,
Markus
On Mon, Apr 15, 2024 at 12:54 PM Zeng Heng <[email protected]> wrote:
> If we fail to allocate propname buffer, we need to drop the reference
> count we just took. Because the pinctrl_dt_free_maps() includes the
> droping operation, here we call it directly.
>
> Fixes: 91d5c5060ee2 ("pinctrl: devicetree: fix null pointer dereferencing in pinctrl_dt_to_map")
> Suggested-by: Dan Carpenter <[email protected]>
> Signed-off-by: Zeng Heng <[email protected]>
Patch applied for fixes.
Yours,
Linus Walleij
On Mon, Apr 15, 2024 at 06:53:28PM +0800, Zeng Heng wrote:
> If we fail to allocate propname buffer, we need to drop the reference
> count we just took. Because the pinctrl_dt_free_maps() includes the
> droping operation, here we call it directly.
..
> for (state = 0; ; state++) {
> /* Retrieve the pinctrl-* property */
> propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
> - if (!propname)
> - return -ENOMEM;
> + if (!propname) {
> + ret = -ENOMEM;
> + goto err;
> + }
> prop = of_find_property(np, propname, &size);
> kfree(propname);
> if (!prop) {
> if (state == 0) {
> - of_node_put(np);
> - return -ENODEV;
> + ret = -ENODEV;
> + goto err;
Has it been tested? How on earth is this a correct change?
We iterate over state numbers until we have properties available. This chunk is
_successful_ exit path, we may not free parsed maps! Am I wrong?
> }
> break;
> }
--
With Best Regards,
Andy Shevchenko
On Wed, Apr 17, 2024 at 06:30:59PM +0300, Andy Shevchenko wrote:
> On Mon, Apr 15, 2024 at 06:53:28PM +0800, Zeng Heng wrote:
> > If we fail to allocate propname buffer, we need to drop the reference
> > count we just took. Because the pinctrl_dt_free_maps() includes the
> > droping operation, here we call it directly.
>
> ...
>
> > for (state = 0; ; state++) {
> > /* Retrieve the pinctrl-* property */
> > propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
> > - if (!propname)
> > - return -ENOMEM;
> > + if (!propname) {
> > + ret = -ENOMEM;
> > + goto err;
> > + }
> > prop = of_find_property(np, propname, &size);
> > kfree(propname);
> > if (!prop) {
> > if (state == 0) {
> > - of_node_put(np);
> > - return -ENODEV;
> > + ret = -ENODEV;
> > + goto err;
>
> Has it been tested? How on earth is this a correct change?
>
> We iterate over state numbers until we have properties available. This chunk is
> _successful_ exit path, we may not free parsed maps! Am I wrong?
In this path state == 0 so we haven't had a successful iteration yet.
regards,
dan carpenter
On Wed, Apr 17, 2024 at 06:38:46PM +0300, Dan Carpenter wrote:
> On Wed, Apr 17, 2024 at 06:30:59PM +0300, Andy Shevchenko wrote:
> > On Mon, Apr 15, 2024 at 06:53:28PM +0800, Zeng Heng wrote:
..
> > > for (state = 0; ; state++) {
> > > /* Retrieve the pinctrl-* property */
> > > propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
> > > - if (!propname)
> > > - return -ENOMEM;
> > > + if (!propname) {
> > > + ret = -ENOMEM;
> > > + goto err;
> > > + }
> > > prop = of_find_property(np, propname, &size);
> > > kfree(propname);
> > > if (!prop) {
> > > if (state == 0) {
> > > - of_node_put(np);
> > > - return -ENODEV;
> > > + ret = -ENODEV;
> > > + goto err;
> >
> > Has it been tested? How on earth is this a correct change?
> >
> > We iterate over state numbers until we have properties available. This chunk is
> > _successful_ exit path, we may not free parsed maps! Am I wrong?
>
> In this path state == 0 so we haven't had a successful iteration yet.
Ah, indeed, this is not a status. Okay, makes sense, but calling that free
function for the purpose of the putting of_node seems an overkill...
--
With Best Regards,
Andy Shevchenko
On Wed, Apr 17, 2024 at 08:12:23PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 17, 2024 at 06:38:46PM +0300, Dan Carpenter wrote:
> > On Wed, Apr 17, 2024 at 06:30:59PM +0300, Andy Shevchenko wrote:
> > > On Mon, Apr 15, 2024 at 06:53:28PM +0800, Zeng Heng wrote:
>
> ...
>
> > > > for (state = 0; ; state++) {
> > > > /* Retrieve the pinctrl-* property */
> > > > propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
> > > > - if (!propname)
> > > > - return -ENOMEM;
> > > > + if (!propname) {
> > > > + ret = -ENOMEM;
> > > > + goto err;
> > > > + }
> > > > prop = of_find_property(np, propname, &size);
> > > > kfree(propname);
> > > > if (!prop) {
> > > > if (state == 0) {
> > > > - of_node_put(np);
> > > > - return -ENODEV;
> > > > + ret = -ENODEV;
> > > > + goto err;
> > >
> > > Has it been tested? How on earth is this a correct change?
> > >
> > > We iterate over state numbers until we have properties available. This chunk is
> > > _successful_ exit path, we may not free parsed maps! Am I wrong?
> >
> > In this path state == 0 so we haven't had a successful iteration yet.
>
> Ah, indeed, this is not a status. Okay, makes sense, but calling that free
> function for the purpose of the putting of_node seems an overkill...
Sure, that's one way to look at it, but it's suspicious looking when
there is a direct return which is surrounded by gotos. As I write this,
I remember that Smatch has a warning for code like that.
Probably we should add a comment to say:
/* Return -ENODEV if the property 'pinctrl-0' is not present. */
regards,
dan carpenter
On Wed, Apr 17, 2024 at 08:49:42PM +0300, Dan Carpenter wrote:
> On Wed, Apr 17, 2024 at 08:12:23PM +0300, Andy Shevchenko wrote:
> > On Wed, Apr 17, 2024 at 06:38:46PM +0300, Dan Carpenter wrote:
> > > On Wed, Apr 17, 2024 at 06:30:59PM +0300, Andy Shevchenko wrote:
> > > > On Mon, Apr 15, 2024 at 06:53:28PM +0800, Zeng Heng wrote:
..
> > > > > for (state = 0; ; state++) {
> > > > > /* Retrieve the pinctrl-* property */
> > > > > propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
> > > > > - if (!propname)
> > > > > - return -ENOMEM;
> > > > > + if (!propname) {
> > > > > + ret = -ENOMEM;
> > > > > + goto err;
> > > > > + }
> > > > > prop = of_find_property(np, propname, &size);
> > > > > kfree(propname);
> > > > > if (!prop) {
> > > > > if (state == 0) {
> > > > > - of_node_put(np);
> > > > > - return -ENODEV;
> > > > > + ret = -ENODEV;
> > > > > + goto err;
> > > >
> > > > Has it been tested? How on earth is this a correct change?
> > > >
> > > > We iterate over state numbers until we have properties available. This chunk is
> > > > _successful_ exit path, we may not free parsed maps! Am I wrong?
> > >
> > > In this path state == 0 so we haven't had a successful iteration yet.
> >
> > Ah, indeed, this is not a status. Okay, makes sense, but calling that free
> > function for the purpose of the putting of_node seems an overkill...
>
> Sure, that's one way to look at it, but it's suspicious looking when
> there is a direct return which is surrounded by gotos. As I write this,
> I remember that Smatch has a warning for code like that.
>
> Probably we should add a comment to say:
>
> /* Return -ENODEV if the property 'pinctrl-0' is not present. */
Good idea, go for it!
--
With Best Regards,
Andy Shevchenko
On Wed, Apr 17, 2024 at 7:49 PM Dan Carpenter <dan.carpenter@linaroorg> wrote:
> Probably we should add a comment to say:
>
> /* Return -ENODEV if the property 'pinctrl-0' is not present. */
Would you mind sending a oneliner on top to fix this?
Yours,
Linus Walleij