linux-kernel - Re: [PATCH] do not limit locked memory when RLIMIT_MEMLOCK is RLIM

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]

Message-Id: <20070713004408.b7162501.akpm@linux-foundation.org>
Date:	Fri, 13 Jul 2007 00:44:08 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Herbert van den Bergh <Herbert.van.den.Bergh@...cle.com>
Cc:	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	Dave McCracken <dave.mccracken@...cle.com>,
	Chris Mason <chris.mason@...cle.com>
Subject: Re: [PATCH] do not limit locked memory when RLIMIT_MEMLOCK is
 RLIM_INFINITY

On Mon, 09 Jul 2007 17:59:12 -0700 Herbert van den Bergh <Herbert.van.den.Bergh@...cle.com> wrote:

> 
> [resending, since my previous message had tabs converted to spaces]
> 
> This patch fixes a bug in mm/mlock.c on 32-bit architectures that prevents
> a user from locking more than 4GB of shared memory, or allocating more
> than 4GB of shared memory in hugepages, when rlim[RLIMIT_MEMLOCK] is
> set to RLIM_INFINITY.
> 
> Signed-off-by: Herbert van den Bergh <herbert.van.den.bergh@...cle.com>
> Acked-by: Chris Mason <chris.mason@...cle.com>
> 
> --- linux-2.6.22/mm/mlock.c.orig	2007-07-09 10:19:31.000000000 -0700
> +++ linux-2.6.22/mm/mlock.c	2007-07-09 10:19:19.000000000 -0700
> @@ -244,9 +244,12 @@ int user_shm_lock(size_t size, struct us
>  
>  	locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
>  	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
> +	if (lock_limit == RLIM_INFINITY)
> +		allowed = 1;
>  	lock_limit >>= PAGE_SHIFT;
>  	spin_lock(&shmlock_user_lock);
> -	if (locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK))
> +	if (!allowed &&
> +	    locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK))
>  		goto out;
>  	get_uid(user);
>  	user->locked_shm += locked;

OK.  Seems like a nasty bug if one happens to want to do that.  Should we
backport this into 2.6.22.x?

-
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/