Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265208AbTFMHJO (ORCPT ); Fri, 13 Jun 2003 03:09:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265218AbTFMHJO (ORCPT ); Fri, 13 Jun 2003 03:09:14 -0400 Received: from cerebus.wirex.com ([65.102.14.138]:2036 "EHLO figure1.int.wirex.com") by vger.kernel.org with ESMTP id S265208AbTFMHJC (ORCPT ); Fri, 13 Jun 2003 03:09:02 -0400 Date: Fri, 13 Jun 2003 00:22:24 -0700 From: Chris Wright To: torvalds@transmeta.com, akpm@digeo.com Cc: linux-kernel@vger.kernel.org, linux-security-module@wirex.com, greg@kroah.com, sds@epoch.ncsc.mil Subject: Re: [PATCH][LSM] setfsuid/setgsuid bug fix 4/4 Message-ID: <20030613002224.G31636@figure1.int.wirex.com> Mail-Followup-To: torvalds@transmeta.com, akpm@digeo.com, linux-kernel@vger.kernel.org, linux-security-module@wirex.com, greg@kroah.com, sds@epoch.ncsc.mil References: <20030613001021.D31636@figure1.int.wirex.com> <20030613001521.E31636@figure1.int.wirex.com> <20030613001908.F31636@figure1.int.wirex.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.2.5i In-Reply-To: <20030613001908.F31636@figure1.int.wirex.com>; from chris@wirex.com on Fri, Jun 13, 2003 at 12:19:08AM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2272 Lines: 65 Patch from Jakub Jel?nek [LSM] make sure setfsuid/setfsgid return values are right. Before include/linux/security.h was added, setfsuid/setfsgid always returned old_fsuid, no matter if the fsuid was actually changed or not. With the default security ops it seems to do the same, because both security_task_setuid and security_task_post_setuid return 0, but these are hooks which seem to return 0 on success, -errno on failure, so if some non-default security hook is installed and ever returns -errno in setfsuid/setfsgid, -errno will be returned from the syscall instead of the expected old_fsuid. This makes it hard to distinguish uids 0xfffff001 .. 0xffffffff from errors of security hooks. --- linus-2.5/kernel/sys.c.setfsuid Thu Jun 12 22:53:14 2003 +++ linus-2.5/kernel/sys.c Thu Jun 12 22:53:14 2003 @@ -831,13 +831,11 @@ asmlinkage long sys_setfsuid(uid_t uid) { int old_fsuid; - int retval; - - retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); - if (retval) - return retval; old_fsuid = current->fsuid; + if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) + return old_fsuid; + if (uid == current->uid || uid == current->euid || uid == current->suid || uid == current->fsuid || capable(CAP_SETUID)) @@ -850,9 +848,7 @@ current->fsuid = uid; } - retval = security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); - if (retval) - return retval; + security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); return old_fsuid; } @@ -863,13 +859,11 @@ asmlinkage long sys_setfsgid(gid_t gid) { int old_fsgid; - int retval; - - retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS); - if (retval) - return retval; old_fsgid = current->fsgid; + if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) + return old_fsgid; + if (gid == current->gid || gid == current->egid || gid == current->sgid || gid == current->fsgid || capable(CAP_SETGID)) - 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/