Re: [PATCH net] net/smc: fix a memory leak in smc_sysctl_net_exit()

[Tony Lu <tonylu@linux.alibaba.com>]

On Fri, Mar 25, 2022 at 09:50:21AM -0700, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
> 
> Recently added smc_sysctl_net_exit() forgot to free
> the memory allocated from smc_sysctl_net_init()
> for non initial network namespace.
> 
> Fixes: 462791bbfa35 ("net/smc: add sysctl interface for SMC")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Cc: Tony Lu <tonylu@linux.alibaba.com>
> Cc: Dust Li <dust.li@linux.alibaba.com>
> ---
>  net/smc/smc_sysctl.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c
> index bae19419e7553222d74c2ae178fd5a2b6116679b..cf3ab1334c009a1a0539b2c228c4503ae391d89b 100644
> --- a/net/smc/smc_sysctl.c
> +++ b/net/smc/smc_sysctl.c
> @@ -61,5 +61,10 @@ int __net_init smc_sysctl_net_init(struct net *net)
>  
>  void __net_exit smc_sysctl_net_exit(struct net *net)
>  {
> +	struct ctl_table *table;
> +
> +	table = net->smc.smc_hdr->ctl_table_arg;
>  	unregister_net_sysctl_table(net->smc.smc_hdr);
> +	if (!net_eq(net, &init_net))
> +		kfree(table);
>  }

Thanks a lot for fixing this issue, this is my fault.

Tony Lu