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Message-ID: <4DEE754B.1020706@suse.cz>
Date: Tue, 07 Jun 2011 21:00:27 +0200
From: Jiri Slaby <jslaby@suse.cz>
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To: Oleg Nesterov <oleg@redhat.com>
CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
        Alan Cox <alan@lxorguk.ukuu.org.uk>, Al Viro <viro@zeniv.linux.org.uk>,
        Andi Kleen <andi@firstfloor.org>, Xiaotian Feng <dfeng@redhat.com>,
        Neil Horman <nhorman@tuxdriver.com>, Jiri Slaby <jirislaby@gmail.com>
Subject: Re: [PATCH] do_coredump: fix the "ispipe" error check
References: <1307457010-7241-1-git-send-email-jslaby@suse.cz> <20110607181607.GA3732@redhat.com> <20110607183542.GA5559@redhat.com>
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On 06/07/2011 08:35 PM, Oleg Nesterov wrote:
> do_coredump() assumes that if format_corename() fails it should
> return -ENOMEM. This is not true, for example cn_print_exe_file()
> can propagate the error from d_path. Even if it was true, this is
> too fragile. Change the code to check "ispipe < 0".
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Acked-by: Jiri Slaby <jslaby@suse.cz>

> ---
> 
>  fs/exec.c |   12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> --- ptrace/fs/exec.c~corename_errcode	2011-06-07 19:44:30.000000000 +0200
> +++ ptrace/fs/exec.c	2011-06-07 20:20:48.000000000 +0200
> @@ -2092,16 +2092,16 @@ void do_coredump(long signr, int exit_co
>  
>  	ispipe = format_corename(&cn, signr);
>  
> -	if (ispipe == -ENOMEM) {
> -		printk(KERN_WARNING "format_corename failed\n");
> -		printk(KERN_WARNING "Aborting core\n");
> -		goto fail_corename;
> -	}
> -
>   	if (ispipe) {
>  		int dump_count;
>  		char **helper_argv;
>  
> +		if (ispipe < 0) {
> +			printk(KERN_WARNING "format_corename failed\n");
> +			printk(KERN_WARNING "Aborting core\n");
> +			goto fail_corename;
> +		}
> +
>  		if (cprm.limit == 1) {
>  			/*
>  			 * Normally core limits are irrelevant to pipes, since
> 

thanks,
-- 
js
suse labs