Re: [PATCH] tty/n_gsm.c: fix a memory leak in gsmld_open

[Jiri Slaby <jslaby@suse.cz>]

On 07/28/2014 10:14 AM, xinhui.pan wrote:
> If gsmld_attach_gsm fails, the gsm is not used anymore.
> tty core will not call gsmld_close to do the cleanup work.
> tty core just restore to the tty old ldisc.
> That always causes memory leak.

Nice catch!

> --- a/drivers/tty/n_gsm.c
> +++ b/drivers/tty/n_gsm.c
> @@ -2382,7 +2383,13 @@ static int gsmld_open(struct tty_struct *tty)
>  
>  	/* Attach the initial passive connection */
>  	gsm->encoding = 1;
> -	return gsmld_attach_gsm(tty, gsm);
> +
> +	ret = gsmld_attach_gsm(tty, gsm);
> +	if (ret != 0) {
> +		gsm_cleanup_mux(gsm);
> +		mux_put(gsm);

It is quite illogical to put the mux here. It should be in gsmld_open.
I.e. gsm_cleanup_mux here, mux_put there.

thanks,
-- 
js
suse labs