[PATCH] net: openvswitch: fix possible memory leak in ovs_meter_cmd_set()

[PATCH] net: openvswitch: fix possible memory leak in ovs_meter_cmd_set()

[Hangyu Hua]

old_meter needs to be free after it is detached regardless of whether
the new meter is successfully attached.

Fixes: c7c4c44c9a95 ("net: openvswitch: expand the meters supported number")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
---
 net/openvswitch/meter.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
index 6e38f68f88c2..e84082e209e9 100644
--- a/net/openvswitch/meter.c
+++ b/net/openvswitch/meter.c
@@ -448,8 +448,10 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
 		goto exit_unlock;
 
 	err = attach_meter(meter_tbl, meter);
-	if (err)
+	if (err) {
+		ovs_meter_free(old_meter);
 		goto exit_unlock;
+	}
 
 	ovs_unlock();
 
-- 
2.34.1

Re: [PATCH] net: openvswitch: fix possible memory leak in ovs_meter_cmd_set()

[Eelco Chaudron]

On 8 Feb 2023, at 8:16, Hangyu Hua wrote:

> old_meter needs to be free after it is detached regardless of whether
> the new meter is successfully attached.
>
> Fixes: c7c4c44c9a95 ("net: openvswitch: expand the meters supported number")
> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
> ---
>  net/openvswitch/meter.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
> index 6e38f68f88c2..e84082e209e9 100644
> --- a/net/openvswitch/meter.c
> +++ b/net/openvswitch/meter.c
> @@ -448,8 +448,10 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
>  		goto exit_unlock;
>
>  	err = attach_meter(meter_tbl, meter);
> -	if (err)
> +	if (err) {
> +		ovs_meter_free(old_meter);
>  		goto exit_unlock;

It would be nicer to add another goto label like exit_free_old_meter.

+	if (err)
+     	goto exit_free_old_meter:

exit_free_old_meter:
    ovs_meter_free(old_meter);
exit_unlock:
	ovs_unlock();
	nlmsg_free(reply);
exit_free_meter:


Or maybe it would be even nicer to free the old_meter outside of the global lock?

> +	}
>
>  	ovs_unlock();
>
> -- 
> 2.34.1

Re: [PATCH] net: openvswitch: fix possible memory leak in ovs_meter_cmd_set()

[Hangyu Hua]

On 9/2/2023 16:26, Eelco Chaudron wrote:
> 
> 
> On 8 Feb 2023, at 8:16, Hangyu Hua wrote:
> 
>> old_meter needs to be free after it is detached regardless of whether
>> the new meter is successfully attached.
>>
>> Fixes: c7c4c44c9a95 ("net: openvswitch: expand the meters supported number")
>> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
>> ---
>>   net/openvswitch/meter.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
>> index 6e38f68f88c2..e84082e209e9 100644
>> --- a/net/openvswitch/meter.c
>> +++ b/net/openvswitch/meter.c
>> @@ -448,8 +448,10 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
>>   		goto exit_unlock;
>>
>>   	err = attach_meter(meter_tbl, meter);
>> -	if (err)
>> +	if (err) {
>> +		ovs_meter_free(old_meter);
>>   		goto exit_unlock;
> 
> It would be nicer to add another goto label like exit_free_old_meter.
> 
> +	if (err)
> +     	goto exit_free_old_meter:
> 
> exit_free_old_meter:
>      ovs_meter_free(old_meter);
> exit_unlock:
> 	ovs_unlock();
> 	nlmsg_free(reply);
> exit_free_meter:
> 
> 
> Or maybe it would be even nicer to free the old_meter outside of the global lock?
> 
>> +	}
>>
>>   	ovs_unlock();

I get it. I will send a v2.

Thanks,
Hangyu
>>
>> -- 
>> 2.34.1
>