Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756669AbZKSPdX (ORCPT ); Thu, 19 Nov 2009 10:33:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754290AbZKSPdW (ORCPT ); Thu, 19 Nov 2009 10:33:22 -0500 Received: from mail-pz0-f171.google.com ([209.85.222.171]:63347 "EHLO mail-pz0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751966AbZKSPdV (ORCPT ); Thu, 19 Nov 2009 10:33:21 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=D0M8HxYrOvoEaoJ/vOX2nqixuOi0PWDKQKMilNWds2HO8twopFlEiynmCogJy9zc30 WLLVYzGJFTluE3c6Vqd7u2K1s7ZOKrVjTrIFlwkZMCavQ5XoQ55C0LPjrdzrKjIpixfl wdk/yn0jpalIugAE3IzUdmFrYpvgViWeMa3nY= Date: Thu, 19 Nov 2009 23:34:08 +0800 From: =?utf-8?Q?Am=C3=A9rico?= Wang To: Masami Hiramatsu Cc: Ingo Molnar , lkml , Roland McGrath , Oleg Nesterov , Hidehiro Kawai , Andrew Morton , systemtap , DLE Subject: Re: [PATCH -tip 0/2] Fix mm->flags consistency issue in coredump Message-ID: <20091119153408.GB8392@hack> References: <20091117235305.30900.43344.stgit@dhcp-100-2-132.bos.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091117235305.30900.43344.stgit@dhcp-100-2-132.bos.redhat.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2528 Lines: 80 On Tue, Nov 17, 2009 at 06:53:05PM -0500, Masami Hiramatsu wrote: > >Hi, > >These patches are for fixing coredump mm->flags consistency issue. > >--- >1787 if (mm->core_state || !get_dumpable(mm)) { <- (1) >1788 up_write(&mm->mmap_sem); >1789 put_cred(cred); >1790 goto fail; >1791 } >1792 >[...] >1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2) >1799 flag = O_EXCL; /* Stop rewrite attacks */ >1800 cred->fsuid = 0; /* Dump root private */ >1801 } >--- > >Since dumpable bits are not protected by lock, there is a >chance to change these bits between (1) and (2). > >To solve this issue, this patch copies mm->flags to >coredump_params.mm_flags at the beginning of do_coredump() and uses it instead of get_dumpable() while dumping core. >This series also introduce coredump parameter structure >for simplify bimfmt->core_dump interface. So, this patch set hides 'mm_flags' from globally in mm_struct to locally in do_coredump() function, by copying it to a local data structure? Hmm, seems reasonable. Reviewed-by: WANG Cong Thanks. > >Thank you, > >--- > >Masami Hiramatsu (2): > Pass mm->flags as a coredump parameter for consistency > mm: Introduce coredump parameter structure > > > fs/binfmt_aout.c | 13 ++++++----- > fs/binfmt_elf.c | 50 +++++++++++++++++++---------------------- > fs/binfmt_elf_fdpic.c | 38 ++++++++++++------------------- > fs/binfmt_flat.c | 6 ++--- > fs/binfmt_som.c | 2 +- > fs/exec.c | 58 ++++++++++++++++++++++++++++++----------------- > include/linux/binfmts.h | 11 ++++++++- > 7 files changed, 97 insertions(+), 81 deletions(-) > >-- >Masami Hiramatsu > >Software Engineer >Hitachi Computer Products (America), Inc. >Software Solutions Division >e-mail: mhiramat@redhat.com >-- >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html >Please read the FAQ at http://www.tux.org/lkml/ -- Live like a child, think like the god. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/