2022-07-01 07:18:36

by Jianglei Nie

Subject: [PATCH] net: atlantic: fix potential memory leak in aq_ndev_close()

If aq_nic_stop() fails, aq_ndev_close() returns err without calling
aq_nic_deinit() to release the relevant memory and resource, which
will lead to a memory leak.

We can fix it by deleting the if condition judgment and goto statement to
call aq_nic_deinit() directly after aq_nic_stop() to fix the memory leak.

Signed-off-by: Jianglei Nie <[email protected]>
---
drivers/net/ethernet/aquantia/atlantic/aq_main.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_main.c b/drivers/net/ethernet/aquantia/atlantic/aq_main.c
index 88595863d8bc..8a0af371e7dc 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_main.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_main.c
@@ -94,11 +94,8 @@ static int aq_ndev_close(struct net_device *ndev)
int err = 0;

err = aq_nic_stop(aq_nic);
- if (err < 0)
- goto err_exit;
aq_nic_deinit(aq_nic, true);

-err_exit:
return err;
}

--
2.25.1

2022-07-01 15:03:51

by Francois Romieu

Subject: Re: [PATCH] net: atlantic: fix potential memory leak in aq_ndev_close()

Jianglei Nie <[email protected]> :
> If aq_nic_stop() fails, aq_ndev_close() returns err without calling
> aq_nic_deinit() to release the relevant memory and resource, which
> will lead to a memory leak.
>
> We can fix it by deleting the if condition judgment and goto statement to
> call aq_nic_deinit() directly after aq_nic_stop() to fix the memory leak.
>
> Signed-off-by: Jianglei Nie <[email protected]>

Either (1) the hardware is stopped and the relevance of error returning
aq_nic_stop is dubious at best or (2) the hardware is not stopped and
it may not be safe to remove its kernel allocated resources behind its
back.

There is a problem but this patch is imho targeting the symptom.

A knowledgeable answer to (1), (2) could also help to avoid the
dev_{close/open} danse in drivers/net/ethernet/aquantia/atlantic/aq_ethtool.c.

--
Ueimor