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From: Andrew Morton <akpm@osdl.org>
To: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [patch 1/5] binfmt: fix uaccess handling
Date: Thu, 26 Oct 2006 21:37:41 -0700	[thread overview]
Message-ID: <20061026213741.06f7ecb4.akpm@osdl.org> (raw)
In-Reply-To: <20061026130146.GB7127@osiris.boeblingen.de.ibm.com>

On Thu, 26 Oct 2006 15:01:46 +0200
Heiko Carstens <heiko.carstens@de.ibm.com> wrote:

> @@ -254,7 +255,8 @@
>  	p = current->mm->arg_end = current->mm->arg_start;
>  	while (argc-- > 0) {
>  		size_t len;
> -		__put_user((elf_addr_t)p, argv++);
> +		if (__put_user((elf_addr_t)p, argv++))
> +			return -EFAULT;
>  		len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
>  		if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
>  			return 0;

We return EFAULT, but if strnlen_user() gets a fault, we return zero.  But
then, the return value of create_elf_tables() gets cheerfully ignored
anyway.  So I assume we start up some new program with a
partially-constructed environment and it then mysteriously malfunctions.

Nice, eh?

  reply	other threads:[~2006-10-27  4:38 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-26 13:00 [patch 0/5] various user space access fixes Heiko Carstens
2006-10-26 13:01 ` [patch 1/5] binfmt: fix uaccess handling Heiko Carstens
2006-10-27  4:37   ` Andrew Morton [this message]
2006-10-26 13:02 ` [patch 2/5] compat: " Heiko Carstens
2006-10-26 13:03 ` [patch 3/5] net: " Heiko Carstens
2006-10-30 23:06   ` David Miller
2006-10-26 13:04 ` [patch 4/5] profile: " Heiko Carstens
2006-10-26 13:04 ` [patch 5/5] scsi: " Heiko Carstens
2006-10-28 11:31   ` Christoph Hellwig
2006-10-29 21:39     ` Heiko Carstens
2006-12-15 17:36       ` James Bottomley

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