linux-kernel - Re: [PATCH v3 2/3] printk: Fix preferred console selection with multiple matches

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20200213090905.GB36551@google.com>
Date:   Thu, 13 Feb 2020 18:09:05 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
To:     Petr Mladek <pmladek@...e.com>
Cc:     Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 2/3] printk: Fix preferred console selection with
 multiple matches

On (20/02/13 09:39), Petr Mladek wrote:
> > >  	struct console_cmdline *c;
> > >  	int i;
> > > @@ -2131,6 +2131,8 @@ static int __add_preferred_console(char *name, int idx, char *options,
> > >  		if (strcmp(c->name, name) == 0 && c->index == idx) {
> > >  			if (!brl_options)
> > >  				preferred_console = i;
> > > +                       if (user_specified)
> > > +                               c->user_specified = true;
> > >  			return 0;
> > >  		}
> > >  	}

[..]

> > A silly question:
> > 
> > Can the same console first be added by
> > 	console_setup()->__add_preferred_console(true)
> > and then by
> > 	add_preferred_console()->__add_preferred_console(false)
> 
> I guess that this might happen. It should be safe because
> user_specified flag is set only to true when found again,
> see:
> 
>                        if (user_specified)
>                                c->user_specified = true;

Yikes, I didn't see the if-condition. Yes, you are right.

	-ss