[PATCH net v2] octeontx2-pf: Fix potential memory leak in otx2_init_tc()

[PATCH net v2] octeontx2-pf: Fix potential memory leak in otx2_init_tc()

[Ziyang Xuan]

In otx2_init_tc(), if rhashtable_init() failed, it does not free
tc->tc_entries_bitmap which is allocated in otx2_tc_alloc_ent_bitmap().

Fixes: 2e2a8126ffac ("octeontx2-pf: Unify flow management variables")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
---
v2:
  - Remove patch 2 which is not a problem, see the following link:
    https://www.spinics.net/lists/netdev/msg864159.html
---
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
index e64318c110fd..6a01ab1a6e6f 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
@@ -1134,7 +1134,12 @@ int otx2_init_tc(struct otx2_nic *nic)
 		return err;
 
 	tc->flow_ht_params = tc_flow_ht_params;
-	return rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
+	err = rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
+	if (err) {
+		kfree(tc->tc_entries_bitmap);
+		tc->tc_entries_bitmap = NULL;
+	}
+	return err;
 }
 EXPORT_SYMBOL(otx2_init_tc);
 
-- 
2.25.1

Re: [PATCH net v2] octeontx2-pf: Fix potential memory leak in otx2_init_tc()

[Leon Romanovsky]

On Fri, Dec 02, 2022 at 07:04:30PM +0800, Ziyang Xuan wrote:
> In otx2_init_tc(), if rhashtable_init() failed, it does not free
> tc->tc_entries_bitmap which is allocated in otx2_tc_alloc_ent_bitmap().
> 
> Fixes: 2e2a8126ffac ("octeontx2-pf: Unify flow management variables")
> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
> ---
> v2:
>   - Remove patch 2 which is not a problem, see the following link:
>     https://www.spinics.net/lists/netdev/msg864159.html
> ---
>  drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
> index e64318c110fd..6a01ab1a6e6f 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
> @@ -1134,7 +1134,12 @@ int otx2_init_tc(struct otx2_nic *nic)
>  		return err;
>  
>  	tc->flow_ht_params = tc_flow_ht_params;
> -	return rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
> +	err = rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
> +	if (err) {
> +		kfree(tc->tc_entries_bitmap);
> +		tc->tc_entries_bitmap = NULL;

Why do you set NULL here? All callers of otx2_init_tc() unwind error
properly.

> +	}
> +	return err;
>  }
>  EXPORT_SYMBOL(otx2_init_tc);
>  
> -- 
> 2.25.1
> 

Re: [PATCH net v2] octeontx2-pf: Fix potential memory leak in otx2_init_tc()

[Ziyang Xuan (William)]

> On Fri, Dec 02, 2022 at 07:04:30PM +0800, Ziyang Xuan wrote:
>> In otx2_init_tc(), if rhashtable_init() failed, it does not free
>> tc->tc_entries_bitmap which is allocated in otx2_tc_alloc_ent_bitmap().
>>
>> Fixes: 2e2a8126ffac ("octeontx2-pf: Unify flow management variables")
>> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
>> ---
>> v2:
>>   - Remove patch 2 which is not a problem, see the following link:
>>     https://www.spinics.net/lists/netdev/msg864159.html
>> ---
>>  drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
>> index e64318c110fd..6a01ab1a6e6f 100644
>> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
>> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
>> @@ -1134,7 +1134,12 @@ int otx2_init_tc(struct otx2_nic *nic)
>>  		return err;
>>  
>>  	tc->flow_ht_params = tc_flow_ht_params;
>> -	return rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
>> +	err = rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
>> +	if (err) {
>> +		kfree(tc->tc_entries_bitmap);
>> +		tc->tc_entries_bitmap = NULL;
> 
> Why do you set NULL here? All callers of otx2_init_tc() unwind error
> properly.

See the implementation of otx2_tc_alloc_ent_bitmap() as following:

int otx2_tc_alloc_ent_bitmap(struct otx2_nic *nic)
{
	struct otx2_tc_info *tc = &nic->tc_info;

	if (!nic->flow_cfg->max_flows)
		return 0;

	/* Max flows changed, free the existing bitmap */
	kfree(tc->tc_entries_bitmap);
	
	...
}

Hello Leon Romanovsky,

It will kfree(tc->tc_entries_bitmap) firstly, and otx2_tc_alloc_ent_bitmap()
is called by otx2_dl_mcam_count_set() and otx2_init_tc(). I am not sure their
sequence and whether it will cause double free for tc->tc_entries_bitmap. So
setting tc->tc_entries_bitmap to NULL is safe, I think.

Thank you!

> 
>> +	}
>> +	return err;
>>  }
>>  EXPORT_SYMBOL(otx2_init_tc);
>>  
>> -- 
>> 2.25.1
>>
> .
> 

Re: [PATCH net v2] octeontx2-pf: Fix potential memory leak in otx2_init_tc()

[Leon Romanovsky]

On Mon, Dec 05, 2022 at 10:31:02AM +0800, Ziyang Xuan (William) wrote:
> > On Fri, Dec 02, 2022 at 07:04:30PM +0800, Ziyang Xuan wrote:
> >> In otx2_init_tc(), if rhashtable_init() failed, it does not free
> >> tc->tc_entries_bitmap which is allocated in otx2_tc_alloc_ent_bitmap().
> >>
> >> Fixes: 2e2a8126ffac ("octeontx2-pf: Unify flow management variables")
> >> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
> >> ---
> >> v2:
> >>   - Remove patch 2 which is not a problem, see the following link:
> >>     https://www.spinics.net/lists/netdev/msg864159.html
> >> ---
> >>  drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c | 7 ++++++-
> >>  1 file changed, 6 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
> >> index e64318c110fd..6a01ab1a6e6f 100644
> >> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
> >> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
> >> @@ -1134,7 +1134,12 @@ int otx2_init_tc(struct otx2_nic *nic)
> >>  		return err;
> >>  
> >>  	tc->flow_ht_params = tc_flow_ht_params;
> >> -	return rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
> >> +	err = rhashtable_init(&tc->flow_table, &tc->flow_ht_params);
> >> +	if (err) {
> >> +		kfree(tc->tc_entries_bitmap);
> >> +		tc->tc_entries_bitmap = NULL;
> > 
> > Why do you set NULL here? All callers of otx2_init_tc() unwind error
> > properly.
> 
> See the implementation of otx2_tc_alloc_ent_bitmap() as following:
> 
> int otx2_tc_alloc_ent_bitmap(struct otx2_nic *nic)
> {
> 	struct otx2_tc_info *tc = &nic->tc_info;
> 
> 	if (!nic->flow_cfg->max_flows)
> 		return 0;
> 
> 	/* Max flows changed, free the existing bitmap */
> 	kfree(tc->tc_entries_bitmap);

It is worthless call for probe() calls as tc->tc_entries_bitmap is always NULL
at this point for them.

The kfree(tc->tc_entries_bitmap); needs to be moved into otx2_dl_mcam_count_set()
as it is the one place which can change bitmap.

But ok, it is probably too much to request.

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH net v2] octeontx2-pf: Fix potential memory leak in otx2_init_tc()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Fri, 2 Dec 2022 19:04:30 +0800 you wrote:
> In otx2_init_tc(), if rhashtable_init() failed, it does not free
> tc->tc_entries_bitmap which is allocated in otx2_tc_alloc_ent_bitmap().
> 
> Fixes: 2e2a8126ffac ("octeontx2-pf: Unify flow management variables")
> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
> ---
> v2:
>   - Remove patch 2 which is not a problem, see the following link:
>     https://www.spinics.net/lists/netdev/msg864159.html
> 
> [...]

Here is the summary with links:
  - [net,v2] octeontx2-pf: Fix potential memory leak in otx2_init_tc()
    https://git.kernel.org/netdev/net/c/fbf33f5ac76f

You are awesome, thank you!
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