linux-kernel - Re: [PATCH] Fix check after use in kernel/exit.c

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

Date:	Sat, 08 Mar 2008 16:58:21 +0800 (CST)
From:	WANG Cong <xiyou.wangcong@...il.com>
To:	mingo@...e.hu
Cc:	linux-kernel@...r.kernel.org, gvaughan@....nasa.gov, akpm@...l.org,
	jeremy@...p.org
Subject: Re: [PATCH] Fix check after use in kernel/exit.c

From: Ingo Molnar <mingo@...e.hu>
Date: Sat, 8 Mar 2008 09:53:22 +0100

> 
> * Ingo Molnar <mingo@...e.hu> wrote:
> 
> > > @@ -582,9 +582,9 @@ static void exit_mm(struct task_struct * tsk)
> > >  {
> > >  	struct mm_struct *mm = tsk->mm;
> > >  
> > > -	mm_release(tsk, mm);
> > >  	if (!mm)
> > >  		return;
> > > +	mm_release(tsk, mm);
> > 
> > thanks, applied. I'm wondering why this never seems to hit in 
> > practice.
> 
> actually, i unapplied it again because the patch is wrong: mm_release() 
> has side-effects for kernel threads such as the deactivate_mm() [which 
> is important even if the user-mm is NULL]. If the NULL mm dereference 
> can really trigger then it should be avoided within mm_release().
> 

Do you mean that the NULL check should be moved into mm_release()?

Thanks!
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/