2023-02-08 07:17:02

by Hangyu Hua

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

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 <[email protected]>
---
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

2023-02-09 08:27:58

by Eelco Chaudron

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

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 <[email protected]>
> ---
> 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

2023-02-09 08:58:45

by Hangyu Hua

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

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 <[email protected]>
>> ---
>> 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
>