From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757999AbYE0Rsx (ORCPT ); Tue, 27 May 2008 13:48:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754973AbYE0Rsm (ORCPT ); Tue, 27 May 2008 13:48:42 -0400 Received: from sous-sol.org ([216.99.217.87]:47632 "EHLO sous-sol.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754328AbYE0Rsm (ORCPT ); Tue, 27 May 2008 13:48:42 -0400 Date: Tue, 27 May 2008 10:47:38 -0700 From: Chris Wright To: Pekka Enberg Cc: Eric Sesterhenn , linux-kernel@vger.kernel.org, Chris Wright , James Morris , William Lee Irwin III , Andrew Morton , Vegard Nossum Subject: Re: Redzone overwritten with CONFIG_SECURITY Message-ID: <20080527174738.GZ30402@sequoia.sous-sol.org> References: <20080526143422.GA3203@alice> <84144f020805270800l5911ed02ia7a92d96a8aa32a7@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <84144f020805270800l5911ed02ia7a92d96a8aa32a7@mail.gmail.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Pekka Enberg (penberg@cs.helsinki.fi) wrote: > On Mon, May 26, 2008 at 5:34 PM, Eric Sesterhenn wrote: > > i enabled CONFIG_SECURITY on current git and get tons of > > Redzone overwritten errors during early boot, even > > with CONFIG_SECURITY_CAPABILITIES and CONFIG_SECURITY_NETWORK > > disabled. After a while it ends with a kernel panic > > saying: not syncing: Out of memory and no killable process... > > Root partition is ext3 format. > > So what kernel version is this and what's the last known version that > worked? As it's early boot crash, maybe you can try to do git bisect > on it? > > > > > At the moment i dont have a camera at hand, so i'll try > > to write down everything which looks interesting, please tell > > me if i missed something. > > > > The first 24 Bytes of the overwritten section contain > > zeros. Then we have a constant 0x18, and three changing > > values. the next three bites contain exactly the same > > values, first the 0x18, then the two changing ones. > > > > The only value i found so far matching the 0x18 and > > which might be related to CONFIG_SECURITY is CAP_SYS_RESOURCE > > defined in /include/linux/capability.h > > > > BUG hugetlbfs_inode_cache: Redzone overwritten > > > > INFO: 0xccd8e250-0xccd8e253. First byte 0x0 instead of 0xbb > > Info: Slab 0xc119d1c0 objects=12 used=0 fs=0xccd8e000 flags=0x400020c3 > > Info: Object 0xccd8e00 offset=0 fp=0xccd8e280 > > > > Object 0xccd8e00: 00 00 00 ... > > Object 0xccd8e10: 00 00 00 00 00 00 00 00 00 18 e0 d8 cc 18 e0 d8 cc > > Object 0xccd8e20 00 00 00 ... That looks like an addr within the object, like an INIT_LIST_HEAD. > > Pid: 1, comm:swapper Not tainted 2.6.26-rc3-00436-gb373303 #42 > > print_trailer > > check_bytes_and_report > > check_object > > __slab_alloc > > kmem_cache_alloc > > ? hugetlbfs_alloc_inode > > ? hugetlbfs_alloc_inode > > hugetlbfs_alloc_inode > > alloc_inote > > new_inode > > hugetlbs_get_inote > > hugetlbfs_fill_super > > ? sget > > ? set_anon_super > > get_sb_node > > hugetlbfs_get_sb > > ? hugetlbfs_fill_super > > vfs_kern_mount > > kern_mount_data > > init_hugetlbfs_fs > > ? init_once > > ? kernel_init > > kernel_init ok, do_init_calls time frame with that config...CONFIG_SECURITY isn't really doing any allocations, nor much in the way of memory writes. It would get called into via the: hugetlbs_get_inode new_inode alloc_inode security_inode_alloc <-- and that'd be basically a no-op > > Config follows: I couldn't recreate with that config.