[v1] qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure

[PATCH v1] qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure

Posted by Daniil Tatianin 3 years, 3 months ago

adapter->dcb would get silently freed inside qlcnic_dcb_enable() in
case qlcnic_dcb_attach() would return an error, which always happens
under OOM conditions. This would lead to use-after-free because both
of the existing callers invoke qlcnic_dcb_get_info() on the obtained
pointer, which is potentially freed at that point.

Propagate errors from qlcnic_dcb_enable(), and instead free the dcb
pointer at callsite.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c | 9 ++++++++-
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h       | 5 ++---
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c      | 9 ++++++++-
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
index dbb800769cb6..465f149d94d4 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
@@ -2505,7 +2505,14 @@ int qlcnic_83xx_init(struct qlcnic_adapter *adapter)
 		goto disable_mbx_intr;
 
 	qlcnic_83xx_clear_function_resources(adapter);
-	qlcnic_dcb_enable(adapter->dcb);
+
+	err = qlcnic_dcb_enable(adapter->dcb);
+	if (err) {
+		qlcnic_clear_dcb_ops(adapter->dcb);
+		adapter->dcb = NULL;
+		goto disable_mbx_intr;
+	}
+
 	qlcnic_83xx_initialize_nic(adapter, 1);
 	qlcnic_dcb_get_info(adapter->dcb);
 
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
index 7519773eaca6..e1460f9c38bf 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
@@ -112,9 +112,8 @@ static inline void qlcnic_dcb_init_dcbnl_ops(struct qlcnic_dcb *dcb)
 		dcb->ops->init_dcbnl_ops(dcb);
 }
 
-static inline void qlcnic_dcb_enable(struct qlcnic_dcb *dcb)
+static inline int qlcnic_dcb_enable(struct qlcnic_dcb *dcb)
 {
-	if (dcb && qlcnic_dcb_attach(dcb))
-		qlcnic_clear_dcb_ops(dcb);
+	return dcb ? qlcnic_dcb_attach(dcb) : 0;
 }
 #endif
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
index 28476b982bab..36ba15fc9776 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
@@ -2599,7 +2599,14 @@ qlcnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			 "Device does not support MSI interrupts\n");
 
 	if (qlcnic_82xx_check(adapter)) {
-		qlcnic_dcb_enable(adapter->dcb);
+		err = qlcnic_dcb_enable(adapter->dcb);
+		if (err) {
+			qlcnic_clear_dcb_ops(adapter->dcb);
+			adapter->dcb = NULL;
+			dev_err(&pdev->dev, "Failed to enable DCB\n");
+			goto err_out_free_hw;
+		}
+
 		qlcnic_dcb_get_info(adapter->dcb);
 		err = qlcnic_setup_intr(adapter);
 
-- 
2.25.1

Re: [PATCH v1] qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure

Posted by Michal Swiatkowski 3 years, 3 months ago

On Tue, Dec 20, 2022 at 03:56:49PM +0300, Daniil Tatianin wrote:
> adapter->dcb would get silently freed inside qlcnic_dcb_enable() in
> case qlcnic_dcb_attach() would return an error, which always happens
> under OOM conditions. This would lead to use-after-free because both
> of the existing callers invoke qlcnic_dcb_get_info() on the obtained
> pointer, which is potentially freed at that point.
> 
> Propagate errors from qlcnic_dcb_enable(), and instead free the dcb
> pointer at callsite.
> 
> Found by Linux Verification Center (linuxtesting.org) with the SVACE
> static analysis tool.
> 
> Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>

Please add Fix tag and net as target (net-next is close till the end of
this year)

> ---
>  drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c | 9 ++++++++-
>  drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h       | 5 ++---
>  drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c      | 9 ++++++++-
>  3 files changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
> index dbb800769cb6..465f149d94d4 100644
> --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
> +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
> @@ -2505,7 +2505,14 @@ int qlcnic_83xx_init(struct qlcnic_adapter *adapter)
>  		goto disable_mbx_intr;
>  
>  	qlcnic_83xx_clear_function_resources(adapter);
> -	qlcnic_dcb_enable(adapter->dcb);
> +
> +	err = qlcnic_dcb_enable(adapter->dcb);
> +	if (err) {
> +		qlcnic_clear_dcb_ops(adapter->dcb);
> +		adapter->dcb = NULL;
> +		goto disable_mbx_intr;
> +	}

Maybe I miss sth but it looks like there can be memory leak.
For example if error in attach happen after allocating of dcb->cfg.
Isn't it better to call qlcnic_dcb_free instead of qlcnic_clear_dcb_ops?

> +
>  	qlcnic_83xx_initialize_nic(adapter, 1);
>  	qlcnic_dcb_get_info(adapter->dcb);
>  
> diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
> index 7519773eaca6..e1460f9c38bf 100644
> --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
> +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
> @@ -112,9 +112,8 @@ static inline void qlcnic_dcb_init_dcbnl_ops(struct qlcnic_dcb *dcb)
>  		dcb->ops->init_dcbnl_ops(dcb);
>  }
>  
> -static inline void qlcnic_dcb_enable(struct qlcnic_dcb *dcb)
> +static inline int qlcnic_dcb_enable(struct qlcnic_dcb *dcb)
>  {
> -	if (dcb && qlcnic_dcb_attach(dcb))
> -		qlcnic_clear_dcb_ops(dcb);
> +	return dcb ? qlcnic_dcb_attach(dcb) : 0;
>  }
>  #endif
> diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
> index 28476b982bab..36ba15fc9776 100644
> --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
> +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
> @@ -2599,7 +2599,14 @@ qlcnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  			 "Device does not support MSI interrupts\n");
>  
>  	if (qlcnic_82xx_check(adapter)) {
> -		qlcnic_dcb_enable(adapter->dcb);
> +		err = qlcnic_dcb_enable(adapter->dcb);
> +		if (err) {
> +			qlcnic_clear_dcb_ops(adapter->dcb);
> +			adapter->dcb = NULL;
> +			dev_err(&pdev->dev, "Failed to enable DCB\n");
> +			goto err_out_free_hw;
> +		}
> +
>  		qlcnic_dcb_get_info(adapter->dcb);
>  		err = qlcnic_setup_intr(adapter);
>  
> -- 
> 2.25.1
>

Re: [PATCH v1] qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure

Posted by Daniil Tatianin 3 years, 3 months ago

On 12/20/22 4:32 PM, Michal Swiatkowski wrote:
> On Tue, Dec 20, 2022 at 03:56:49PM +0300, Daniil Tatianin wrote:
>> adapter->dcb would get silently freed inside qlcnic_dcb_enable() in
>> case qlcnic_dcb_attach() would return an error, which always happens
>> under OOM conditions. This would lead to use-after-free because both
>> of the existing callers invoke qlcnic_dcb_get_info() on the obtained
>> pointer, which is potentially freed at that point.
>>
>> Propagate errors from qlcnic_dcb_enable(), and instead free the dcb
>> pointer at callsite.
>>
>> Found by Linux Verification Center (linuxtesting.org) with the SVACE
>> static analysis tool.
>>
>> Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
> 
> Please add Fix tag and net as target (net-next is close till the end of
> this year)
>
Sorry, I'll include a fixes tag.
Could you please explain what I would have to do to add net as target?
>> ---
>>   drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c | 9 ++++++++-
>>   drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h       | 5 ++---
>>   drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c      | 9 ++++++++-
>>   3 files changed, 18 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
>> index dbb800769cb6..465f149d94d4 100644
>> --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
>> +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
>> @@ -2505,7 +2505,14 @@ int qlcnic_83xx_init(struct qlcnic_adapter *adapter)
>>   		goto disable_mbx_intr;
>>   
>>   	qlcnic_83xx_clear_function_resources(adapter);
>> -	qlcnic_dcb_enable(adapter->dcb);
>> +
>> +	err = qlcnic_dcb_enable(adapter->dcb);
>> +	if (err) {
>> +		qlcnic_clear_dcb_ops(adapter->dcb);
>> +		adapter->dcb = NULL;
>> +		goto disable_mbx_intr;
>> +	}
> 
> Maybe I miss sth but it looks like there can be memory leak.
> For example if error in attach happen after allocating of dcb->cfg.
> Isn't it better to call qlcnic_dcb_free instead of qlcnic_clear_dcb_ops?
I think you're right, if attach fails midway then we might leak cfg or 
something else.
I'll use qlcnic_dcb_free() instead and completely remove 
qlcnic_clear_dcb_ops() as it
seems to be unused and relies on dcb being in a very specific state.
>> +
>>   	qlcnic_83xx_initialize_nic(adapter, 1);
>>   	qlcnic_dcb_get_info(adapter->dcb);
>>   
>> diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
>> index 7519773eaca6..e1460f9c38bf 100644
>> --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
>> +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h
>> @@ -112,9 +112,8 @@ static inline void qlcnic_dcb_init_dcbnl_ops(struct qlcnic_dcb *dcb)
>>   		dcb->ops->init_dcbnl_ops(dcb);
>>   }
>>   
>> -static inline void qlcnic_dcb_enable(struct qlcnic_dcb *dcb)
>> +static inline int qlcnic_dcb_enable(struct qlcnic_dcb *dcb)
>>   {
>> -	if (dcb && qlcnic_dcb_attach(dcb))
>> -		qlcnic_clear_dcb_ops(dcb);
>> +	return dcb ? qlcnic_dcb_attach(dcb) : 0;
>>   }
>>   #endif
>> diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
>> index 28476b982bab..36ba15fc9776 100644
>> --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
>> +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
>> @@ -2599,7 +2599,14 @@ qlcnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>>   			 "Device does not support MSI interrupts\n");
>>   
>>   	if (qlcnic_82xx_check(adapter)) {
>> -		qlcnic_dcb_enable(adapter->dcb);
>> +		err = qlcnic_dcb_enable(adapter->dcb);
>> +		if (err) {
>> +			qlcnic_clear_dcb_ops(adapter->dcb);
>> +			adapter->dcb = NULL;
>> +			dev_err(&pdev->dev, "Failed to enable DCB\n");
>> +			goto err_out_free_hw;
>> +		}
>> +
>>   		qlcnic_dcb_get_info(adapter->dcb);
>>   		err = qlcnic_setup_intr(adapter);
>>   
>> -- 
>> 2.25.1
>>

Re: [PATCH v1] qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure

Posted by Michal Swiatkowski 3 years, 3 months ago

On Wed, Dec 21, 2022 at 10:47:29AM +0300, Daniil Tatianin wrote:
> On 12/20/22 4:32 PM, Michal Swiatkowski wrote:
> > On Tue, Dec 20, 2022 at 03:56:49PM +0300, Daniil Tatianin wrote:
> > > adapter->dcb would get silently freed inside qlcnic_dcb_enable() in
> > > case qlcnic_dcb_attach() would return an error, which always happens
> > > under OOM conditions. This would lead to use-after-free because both
> > > of the existing callers invoke qlcnic_dcb_get_info() on the obtained
> > > pointer, which is potentially freed at that point.
> > > 
> > > Propagate errors from qlcnic_dcb_enable(), and instead free the dcb
> > > pointer at callsite.
> > > 
> > > Found by Linux Verification Center (linuxtesting.org) with the SVACE
> > > static analysis tool.
> > > 
> > > Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
> > 
> > Please add Fix tag and net as target (net-next is close till the end of
> > this year)
> > 
> Sorry, I'll include a fixes tag.
> Could you please explain what I would have to do to add net as target?

Sorry, maybe it was bad wording. I meant to have PATCH net v2 in title.
For example by adding to git format-patch:
--subject-prefix="PATCH net v2"

> > > ---
> > >   drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c | 9 ++++++++-
> > >   drivers/net/ethernet/qlogic/qlcnic/qlcnic_dcb.h       | 5 ++---
> > >   drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c      | 9 ++++++++-
> > >   3 files changed, 18 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
> > > index dbb800769cb6..465f149d94d4 100644
> > > --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
> > > +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
> > > @@ -2505,7 +2505,14 @@ int qlcnic_83xx_init(struct qlcnic_adapter *adapter)
> > >   		goto disable_mbx_intr;
> > >   	qlcnic_83xx_clear_function_resources(adapter);
> > > -	qlcnic_dcb_enable(adapter->dcb);
> > > +
> > > +	err = qlcnic_dcb_enable(adapter->dcb);
> > > +	if (err) {
> > > +		qlcnic_clear_dcb_ops(adapter->dcb);
> > > +		adapter->dcb = NULL;
> > > +		goto disable_mbx_intr;
> > > +	}
> > 
> > Maybe I miss sth but it looks like there can be memory leak.
> > For example if error in attach happen after allocating of dcb->cfg.
> > Isn't it better to call qlcnic_dcb_free instead of qlcnic_clear_dcb_ops?
> I think you're right, if attach fails midway then we might leak cfg or
> something else.
> I'll use qlcnic_dcb_free() instead and completely remove
> qlcnic_clear_dcb_ops() as it
> seems to be unused and relies on dcb being in a very specific state.

Great, thanks

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