Re: [PATCH 3/4] net: caif: fix memory leak in caif_device_notify

[Pavel Skripkin <paskripkin@gmail.com>]

On Thu,  3 Jun 2021 19:39:11 +0300
Pavel Skripkin <paskripkin@gmail.com> wrote:

> In case of caif_enroll_dev() fail, allocated
> link_support won't be assigned to the corresponding
> structure. So simply free allocated pointer in case
> of error
> 
> Fixes: 7c18d2205ea7 ("caif: Restructure how link caif link layer
> enroll") Cc: stable@vger.kernel.org
> Reported-and-tested-by:
> syzbot+7ec324747ce876a29db6@syzkaller.appspotmail.com Signed-off-by:
> Pavel Skripkin <paskripkin@gmail.com> ---
>  net/caif/caif_dev.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
> index fffbe41440b3..440139706130 100644
> --- a/net/caif/caif_dev.c
> +++ b/net/caif/caif_dev.c
> @@ -370,6 +370,7 @@ static int caif_device_notify(struct
> notifier_block *me, unsigned long what, struct cflayer *layer,
> *link_support; int head_room = 0;
>  	struct caif_device_entry_list *caifdevs;
> +	int res;
>  
>  	cfg = get_cfcnfg(dev_net(dev));
>  	caifdevs = caif_device_list(dev_net(dev));
> @@ -395,8 +396,10 @@ static int caif_device_notify(struct
> notifier_block *me, unsigned long what, break;
>  			}
>  		}
> -		caif_enroll_dev(dev, caifdev, link_support,
> head_room,
> +		res = caif_enroll_dev(dev, caifdev, link_support,
> head_room, &layer, NULL);
> +		if (res)
> +			cfserl_release(link_support);
>  		caifdev->flowctrl = dev_flowctrl;
>  		break;
>  

One thing Im wondering about is should I return this error
from caif_device_notify()? I look forward to hearing your perspective on
this question and patch series :)



With regards,
Pavel Skripkin