2022-12-02 11:31:05

by Ziyang Xuan (William)

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

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 <[email protected]>
---
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


2022-12-04 13:27:12

by Leon Romanovsky

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

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 <[email protected]>
> ---
> 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
>

2022-12-05 02:46:17

by Ziyang Xuan (William)

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

> 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 <[email protected]>
>> ---
>> 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
>>
> .
>

2022-12-05 08:06:38

by Leon Romanovsky

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

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 <[email protected]>
> >> ---
> >> 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 <[email protected]>

2022-12-05 12:08:02

by patchwork-bot+netdevbpf

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

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:

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 <[email protected]>
> ---
> 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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