[PATCH] net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering

[PATCH] net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering

[José Expósito]

Addresses-Coverity-ID: 1492897 ("Resource leak")
Addresses-Coverity-ID: 1492899 ("Resource leak")
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 drivers/net/dsa/ocelot/felix.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 327cc4654806..f1a05e7dc818 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -290,8 +290,11 @@ static int felix_setup_mmio_filtering(struct felix *felix)
 		}
 	}
 
-	if (cpu < 0)
+	if (cpu < 0) {
+		kfree(tagging_rule);
+		kfree(redirect_rule);
 		return -EINVAL;
+	}
 
 	tagging_rule->key_type = OCELOT_VCAP_KEY_ETYPE;
 	*(__be16 *)tagging_rule->key.etype.etype.value = htons(ETH_P_1588);
-- 
2.25.1

Re: [PATCH] net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering

[Vladimir Oltean]

On Wed, Dec 08, 2021 at 07:05:09PM +0100, José Expósito wrote:
> Addresses-Coverity-ID: 1492897 ("Resource leak")
> Addresses-Coverity-ID: 1492899 ("Resource leak")
> Signed-off-by: José Expósito <jose.exposito89@gmail.com>
> ---

Impossible memory leak, I might add, because DSA will error out much
soon if there isn't any CPU port defined:
https://elixir.bootlin.com/linux/v5.15.7/source/net/dsa/dsa2.c#L374
I don't think I should have added the "if (cpu < 0)" check at all, but
then it would have raised other flags, about BIT(negative number) or
things like that. I don't know what's the best way to deal with this?

Anyway, in case we find no better alternative:

Fixes: 8d5f7954b7c8 ("net: dsa: felix: break at first CPU port during init and teardown")
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>

>  drivers/net/dsa/ocelot/felix.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
> index 327cc4654806..f1a05e7dc818 100644
> --- a/drivers/net/dsa/ocelot/felix.c
> +++ b/drivers/net/dsa/ocelot/felix.c
> @@ -290,8 +290,11 @@ static int felix_setup_mmio_filtering(struct felix *felix)
>  		}
>  	}
>  
> -	if (cpu < 0)
> +	if (cpu < 0) {
> +		kfree(tagging_rule);
> +		kfree(redirect_rule);
>  		return -EINVAL;
> +	}
>  
>  	tagging_rule->key_type = OCELOT_VCAP_KEY_ETYPE;
>  	*(__be16 *)tagging_rule->key.etype.etype.value = htons(ETH_P_1588);
> -- 
> 2.25.1
>

Re: [PATCH] net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering

[Jakub Kicinski]

On Wed, 8 Dec 2021 18:13:32 +0000 Vladimir Oltean wrote:
> On Wed, Dec 08, 2021 at 07:05:09PM +0100, José Expósito wrote:
> > Addresses-Coverity-ID: 1492897 ("Resource leak")
> > Addresses-Coverity-ID: 1492899 ("Resource leak")
> > Signed-off-by: José Expósito <jose.exposito89@gmail.com>
> > ---  
> 
> Impossible memory leak, I might add, because DSA will error out much
> soon if there isn't any CPU port defined:
> https://elixir.bootlin.com/linux/v5.15.7/source/net/dsa/dsa2.c#L374
> I don't think I should have added the "if (cpu < 0)" check at all, but
> then it would have raised other flags, about BIT(negative number) or
> things like that. I don't know what's the best way to deal with this?
> 
> Anyway, in case we find no better alternative:
> 
> Fixes: 8d5f7954b7c8 ("net: dsa: felix: break at first CPU port during init and teardown")
> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>

If this is the way to go please repost with the tags added
and a commit message.

Re: [PATCH] net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering

[José Expósito]

On Wed, Dec 08, 2021 at 03:10:30PM -0800, Jakub Kicinski wrote:
> On Wed, 8 Dec 2021 18:13:32 +0000 Vladimir Oltean wrote:
> > Impossible memory leak, I might add, because DSA will error out much
> > soon if there isn't any CPU port defined:
> > https://elixir.bootlin.com/linux/v5.15.7/source/net/dsa/dsa2.c#L374
> > I don't think I should have added the "if (cpu < 0)" check at all, but
> > then it would have raised other flags, about BIT(negative number) or
> > things like that. I don't know what's the best way to deal with this?
> > 
> > Anyway, in case we find no better alternative:
> > 
> > Fixes: 8d5f7954b7c8 ("net: dsa: felix: break at first CPU port during init and teardown")
> > Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> 
> If this is the way to go please repost with the tags added
> and a commit message.

Thanks for the quick review. I just sent v2 in case you decide to keep
the cpu check:

https://lore.kernel.org/netdev/20211209110538.11585-1-jose.exposito89@gmail.com/T/#u

Jose