From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964826AbWDGRdj (ORCPT ); Fri, 7 Apr 2006 13:33:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964829AbWDGRdj (ORCPT ); Fri, 7 Apr 2006 13:33:39 -0400 Received: from terminus.zytor.com ([192.83.249.54]:1993 "EHLO terminus.zytor.com") by vger.kernel.org with ESMTP id S964826AbWDGRdi (ORCPT ); Fri, 7 Apr 2006 13:33:38 -0400 Message-ID: <4436A260.9070603@zytor.com> Date: Fri, 07 Apr 2006 10:33:20 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 1.5 (X11/20060313) MIME-Version: 1.0 To: Andrew Morton CC: Linux Kernel Mailing List , klibc@zytor.com, Al Viro , hpa@zytor.com, miltonm@bga.com Subject: [PATCH] initramfs: CPIO unpacking fix References: <20060216183745.50cc2bf6.mikey@neuling.org> <20060217160621.99b0ffd4.mikey@neuling.org> In-Reply-To: <20060217160621.99b0ffd4.mikey@neuling.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Unlink files, symlinks, FIFOs, devices etc. (except directories) before writing them when extracting CPIOs. This stops weird behaviour like: 1) writing through symlinks created in earlier CPIOs. eg foo->bar in the first CPIO. Having foo as a non-link in a subsequent CPIO, results in bar being written and foo remaining as a symlink. 2) if the first version of file foo is larger than foo in a subsequent CPIO, we end up with a mix of the two. ie. neither the first or second version of /foo. 3) special files like devices, fifo etc. can't be overwritten in subsequent CPIOS. With this, the kernel will more closely replicate for i in *.cpio; do cpio --extract --unconditional < $i ; done This is a change but it's regarded as fixing broken functionality. Signed-off-by: Michael Neuling Signed-off-by: H. Peter Anvin init/initramfs.c | 3 +++ 1 files changed, 3 insertions(+) Index: linux-2.6.15/init/initramfs.c =================================================================== --- linux-2.6.15.orig/init/initramfs.c +++ linux-2.6.15/init/initramfs.c @@ -249,6 +249,7 @@ static int __init do_name(void) if (dry_run) return 0; if (S_ISREG(mode)) { + sys_unlink(collected); if (maybe_link() >= 0) { wfd = sys_open(collected, O_WRONLY|O_CREAT, mode); if (wfd >= 0) { @@ -263,6 +264,7 @@ static int __init do_name(void) sys_chmod(collected, mode); } else if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { + sys_unlink(collected); if (maybe_link() == 0) { sys_mknod(collected, mode, rdev); sys_chown(collected, uid, gid); @@ -291,6 +293,7 @@ static int __init do_copy(void) static int __init do_symlink(void) { collected[N_ALIGN(name_len) + body_len] = '\0'; + sys_unlink(collected); sys_symlink(collected + N_ALIGN(name_len), collected); sys_lchown(collected, uid, gid); state = SkipIt;