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[PATCH v3 7/9] vdpa: solidrun: Fix UB bug with devres

Philipp Stanner posted 9 patches 1 year, 5 months ago
There is a newer version of this series
[PATCH v3 7/9] vdpa: solidrun: Fix UB bug with devres
Posted by Philipp Stanner 1 year, 5 months ago 
In psnet_open_pf_bar() and snet_open_vf_bar() a string later passed to
pcim_iomap_regions() is placed on the stack. Neither
pcim_iomap_regions() nor the functions it calls copy that string.

Should the string later ever be used, this, consequently, causes
undefined behavior since the stack frame will by then have disappeared.

Fix the bug by allocating the strings on the heap through
devm_kasprintf().

Cc: stable@vger.kernel.org	# v6.3
Fixes: 51a8f9d7f587 ("virtio: vdpa: new SolidNET DPU driver.")
Reported-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Closes: https://lore.kernel.org/all/74e9109a-ac59-49e2-9b1d-d825c9c9f891@wanadoo.fr/
Suggested-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
---
 drivers/vdpa/solidrun/snet_main.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/vdpa/solidrun/snet_main.c b/drivers/vdpa/solidrun/snet_main.c
index 99428a04068d..67235f6190ef 100644
--- a/drivers/vdpa/solidrun/snet_main.c
+++ b/drivers/vdpa/solidrun/snet_main.c
@@ -555,7 +555,7 @@ static const struct vdpa_config_ops snet_config_ops = {
 
 static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
 {
-	char name[50];
+	char *name;
 	int ret, i, mask = 0;
 	/* We don't know which BAR will be used to communicate..
 	 * We will map every bar with len > 0.
@@ -573,7 +573,10 @@ static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
 		return -ENODEV;
 	}
 
-	snprintf(name, sizeof(name), "psnet[%s]-bars", pci_name(pdev));
+	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
+	if (!name)
+		return -ENOMEM;
+
 	ret = pcim_iomap_regions(pdev, mask, name);
 	if (ret) {
 		SNET_ERR(pdev, "Failed to request and map PCI BARs\n");
@@ -590,10 +593,12 @@ static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
 
 static int snet_open_vf_bar(struct pci_dev *pdev, struct snet *snet)
 {
-	char name[50];
+	char *name;
 	int ret;
 
-	snprintf(name, sizeof(name), "snet[%s]-bar", pci_name(pdev));
+	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
+	if (!name)
+		return -ENOMEM;
 	/* Request and map BAR */
 	ret = pcim_iomap_regions(pdev, BIT(snet->psnet->cfg.vf_bar), name);
 	if (ret) {
-- 
2.46.0
Re: [PATCH v3 7/9] vdpa: solidrun: Fix UB bug with devres
Posted by Andy Shevchenko 1 year, 5 months ago 
On Thu, Aug 22, 2024 at 03:47:39PM +0200, Philipp Stanner wrote:
> In psnet_open_pf_bar() and snet_open_vf_bar() a string later passed to
> pcim_iomap_regions() is placed on the stack. Neither
> pcim_iomap_regions() nor the functions it calls copy that string.
> 
> Should the string later ever be used, this, consequently, causes
> undefined behavior since the stack frame will by then have disappeared.
> 
> Fix the bug by allocating the strings on the heap through
> devm_kasprintf().

...

> -	snprintf(name, sizeof(name), "psnet[%s]-bars", pci_name(pdev));
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
> +	if (!name)
> +		return -ENOMEM;
> +
>  	ret = pcim_iomap_regions(pdev, mask, name);

...

> -	snprintf(name, sizeof(name), "snet[%s]-bar", pci_name(pdev));
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
> +	if (!name)
> +		return -ENOMEM;

+ Blank line as in the above snippet?

>  	/* Request and map BAR */
>  	ret = pcim_iomap_regions(pdev, BIT(snet->psnet->cfg.vf_bar), name);

-- 
With Best Regards,
Andy Shevchenko
Re: [PATCH v3 7/9] vdpa: solidrun: Fix UB bug with devres
Posted by Christophe JAILLET 1 year, 5 months ago 
Le 22/08/2024 à 15:47, Philipp Stanner a écrit :
> In psnet_open_pf_bar() and snet_open_vf_bar() a string later passed to
> pcim_iomap_regions() is placed on the stack. Neither
> pcim_iomap_regions() nor the functions it calls copy that string.
> 
> Should the string later ever be used, this, consequently, causes
> undefined behavior since the stack frame will by then have disappeared.
> 
> Fix the bug by allocating the strings on the heap through
> devm_kasprintf().
> 
> Cc: stable@vger.kernel.org	# v6.3
> Fixes: 51a8f9d7f587 ("virtio: vdpa: new SolidNET DPU driver.")
> Reported-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Closes: https://lore.kernel.org/all/74e9109a-ac59-49e2-9b1d-d825c9c9f891@wanadoo.fr/
> Suggested-by: Andy Shevchenko <andy@kernel.org>
> Signed-off-by: Philipp Stanner <pstanner@redhat.com>
> ---
>   drivers/vdpa/solidrun/snet_main.c | 13 +++++++++----
>   1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vdpa/solidrun/snet_main.c b/drivers/vdpa/solidrun/snet_main.c
> index 99428a04068d..67235f6190ef 100644
> --- a/drivers/vdpa/solidrun/snet_main.c
> +++ b/drivers/vdpa/solidrun/snet_main.c
> @@ -555,7 +555,7 @@ static const struct vdpa_config_ops snet_config_ops = {
>   
>   static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
>   {
> -	char name[50];
> +	char *name;
>   	int ret, i, mask = 0;
>   	/* We don't know which BAR will be used to communicate..
>   	 * We will map every bar with len > 0.
> @@ -573,7 +573,10 @@ static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
>   		return -ENODEV;
>   	}
>   
> -	snprintf(name, sizeof(name), "psnet[%s]-bars", pci_name(pdev));
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
> +	if (!name)
> +		return -ENOMEM;
> +
>   	ret = pcim_iomap_regions(pdev, mask, name);
>   	if (ret) {
>   		SNET_ERR(pdev, "Failed to request and map PCI BARs\n");
> @@ -590,10 +593,12 @@ static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
>   
>   static int snet_open_vf_bar(struct pci_dev *pdev, struct snet *snet)
>   {
> -	char name[50];
> +	char *name;
>   	int ret;
>   
> -	snprintf(name, sizeof(name), "snet[%s]-bar", pci_name(pdev));
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));

s/psnet/snet/

> +	if (!name)
> +		return -ENOMEM;
>   	/* Request and map BAR */
>   	ret = pcim_iomap_regions(pdev, BIT(snet->psnet->cfg.vf_bar), name);
>   	if (ret) {
Re: [PATCH v3 7/9] vdpa: solidrun: Fix UB bug with devres
Posted by Philipp Stanner 1 year, 5 months ago 
On Thu, 2024-08-22 at 16:34 +0200, Christophe JAILLET wrote:
> Le 22/08/2024 à 15:47, Philipp Stanner a écrit :
> > In psnet_open_pf_bar() and snet_open_vf_bar() a string later passed
> > to
> > pcim_iomap_regions() is placed on the stack. Neither
> > pcim_iomap_regions() nor the functions it calls copy that string.
> > 
> > Should the string later ever be used, this, consequently, causes
> > undefined behavior since the stack frame will by then have
> > disappeared.
> > 
> > Fix the bug by allocating the strings on the heap through
> > devm_kasprintf().
> > 
> > Cc: stable@vger.kernel.org	# v6.3
> > Fixes: 51a8f9d7f587 ("virtio: vdpa: new SolidNET DPU driver.")
> > Reported-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > Closes:
> > https://lore.kernel.org/all/74e9109a-ac59-49e2-9b1d-d825c9c9f891@wanadoo.fr/
> > Suggested-by: Andy Shevchenko <andy@kernel.org>
> > Signed-off-by: Philipp Stanner <pstanner@redhat.com>
> > ---
> >   drivers/vdpa/solidrun/snet_main.c | 13 +++++++++----
> >   1 file changed, 9 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/vdpa/solidrun/snet_main.c
> > b/drivers/vdpa/solidrun/snet_main.c
> > index 99428a04068d..67235f6190ef 100644
> > --- a/drivers/vdpa/solidrun/snet_main.c
> > +++ b/drivers/vdpa/solidrun/snet_main.c
> > @@ -555,7 +555,7 @@ static const struct vdpa_config_ops
> > snet_config_ops = {
> >   
> >   static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet
> > *psnet)
> >   {
> > -	char name[50];
> > +	char *name;
> >   	int ret, i, mask = 0;
> >   	/* We don't know which BAR will be used to communicate..
> >   	 * We will map every bar with len > 0.
> > @@ -573,7 +573,10 @@ static int psnet_open_pf_bar(struct pci_dev
> > *pdev, struct psnet *psnet)
> >   		return -ENODEV;
> >   	}
> >   
> > -	snprintf(name, sizeof(name), "psnet[%s]-bars",
> > pci_name(pdev));
> > +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-
> > bars", pci_name(pdev));
> > +	if (!name)
> > +		return -ENOMEM;
> > +
> >   	ret = pcim_iomap_regions(pdev, mask, name);
> >   	if (ret) {
> >   		SNET_ERR(pdev, "Failed to request and map PCI
> > BARs\n");
> > @@ -590,10 +593,12 @@ static int psnet_open_pf_bar(struct pci_dev
> > *pdev, struct psnet *psnet)
> >   
> >   static int snet_open_vf_bar(struct pci_dev *pdev, struct snet
> > *snet)
> >   {
> > -	char name[50];
> > +	char *name;
> >   	int ret;
> >   
> > -	snprintf(name, sizeof(name), "snet[%s]-bar",
> > pci_name(pdev));
> > +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-
> > bars", pci_name(pdev));
> 
> s/psnet/snet/

sharp eyes ;)

Thx,
P.

> 
> > +	if (!name)
> > +		return -ENOMEM;
> >   	/* Request and map BAR */
> >   	ret = pcim_iomap_regions(pdev, BIT(snet->psnet-
> > >cfg.vf_bar), name);
> >   	if (ret) {
>

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