From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6880 invoked by alias); 19 Nov 2009 15:34:56 -0000 Received: (qmail 6872 invoked by uid 22791); 19 Nov 2009 15:34:54 -0000 X-SWARE-Spam-Status: No, hits=-2.6 required=5.0 tests=BAYES_00,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mail-pz0-f199.google.com (HELO mail-pz0-f199.google.com) (209.85.222.199) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 19 Nov 2009 15:33:29 +0000 Received: by pzk37 with SMTP id 37so1590646pzk.10 for ; Thu, 19 Nov 2009 07:33:27 -0800 (PST) Received: by 10.114.86.18 with SMTP id j18mr130365wab.39.1258644806620; Thu, 19 Nov 2009 07:33:26 -0800 (PST) Received: from hack ([58.31.79.117]) by mx.google.com with ESMTPS id 20sm399201pxi.3.2009.11.19.07.33.21 (version=TLSv1/SSLv3 cipher=RC4-MD5); Thu, 19 Nov 2009 07:33:24 -0800 (PST) Date: Thu, 19 Nov 2009 15:34:00 -0000 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) Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2009-q4/txt/msg00599.txt.bz2 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.