From patchwork Wed Jul 16 21:50:34 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 4571841 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id AAA699F26C for ; Wed, 16 Jul 2014 21:53:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CB66920120 for ; Wed, 16 Jul 2014 21:53:58 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E718D2010F for ; Wed, 16 Jul 2014 21:53:57 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1X7X7H-0004DU-Jd; Wed, 16 Jul 2014 21:51:59 +0000 Received: from smtp.outflux.net ([2001:19d0:2:6:c0de:0:736d:7470]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X7X6o-0003zH-Nc for linux-arm-kernel@lists.infradead.org; Wed, 16 Jul 2014 21:51:32 +0000 Received: from www.outflux.net (serenity.outflux.net [10.2.0.2]) by vinyl.outflux.net (8.14.4/8.14.4/Debian-4.1ubuntu1) with ESMTP id s6GLor2u007762; Wed, 16 Jul 2014 14:50:53 -0700 From: Kees Cook To: linux-kernel@vger.kernel.org Subject: [PATCH v11 03/11] seccomp: split mode setting routines Date: Wed, 16 Jul 2014 14:50:34 -0700 Message-Id: <1405547442-26641-4-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1405547442-26641-1-git-send-email-keescook@chromium.org> References: <1405547442-26641-1-git-send-email-keescook@chromium.org> X-MIMEDefang-Filter: outflux$Revision: 1.316 $ X-HELO: www.outflux.net X-Scanned-By: MIMEDefang 2.73 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140716_145130_854256_56264501 X-CRM114-Status: GOOD ( 13.18 ) X-Spam-Score: -2.3 (--) Cc: linux-arch@vger.kernel.org, linux-mips@linux-mips.org, Will Drewry , Kees Cook , linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, x86@kernel.org, James Morris , Oleg Nesterov , Daniel Borkmann , Julien Tinnes , "Michael Kerrisk \(man-pages\)" , Andrew Morton , Andy Lutomirski , David Drysdale , linux-arm-kernel@lists.infradead.org, Alexei Starovoitov X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Separates the two mode setting paths to make things more readable with fewer #ifdefs within function bodies. Signed-off-by: Kees Cook Reviewed-by: Oleg Nesterov Reviewed-by: Andy Lutomirski --- kernel/seccomp.c | 71 ++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 48 insertions(+), 23 deletions(-) diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 9df7def86c3b..05cac2c2eca1 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -489,48 +489,66 @@ long prctl_get_seccomp(void) } /** - * seccomp_set_mode: internal function for setting seccomp mode - * @seccomp_mode: requested mode to use - * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER - * - * This function may be called repeatedly with a @seccomp_mode of - * SECCOMP_MODE_FILTER to install additional filters. Every filter - * successfully installed will be evaluated (in reverse order) for each system - * call the task makes. + * seccomp_set_mode_strict: internal function for setting strict seccomp * * Once current->seccomp.mode is non-zero, it may not be changed. * * Returns 0 on success or -EINVAL on failure. */ -static long seccomp_set_mode(unsigned long seccomp_mode, char __user *filter) +static long seccomp_set_mode_strict(void) { + const unsigned long seccomp_mode = SECCOMP_MODE_STRICT; long ret = -EINVAL; if (!seccomp_may_assign_mode(seccomp_mode)) goto out; - switch (seccomp_mode) { - case SECCOMP_MODE_STRICT: - ret = 0; #ifdef TIF_NOTSC - disable_TSC(); + disable_TSC(); #endif - break; + seccomp_assign_mode(seccomp_mode); + ret = 0; + +out: + + return ret; +} + #ifdef CONFIG_SECCOMP_FILTER - case SECCOMP_MODE_FILTER: - ret = seccomp_attach_user_filter(filter); - if (ret) - goto out; - break; -#endif - default: +/** + * seccomp_set_mode_filter: internal function for setting seccomp filter + * @filter: struct sock_fprog containing filter + * + * This function may be called repeatedly to install additional filters. + * Every filter successfully installed will be evaluated (in reverse order) + * for each system call the task makes. + * + * Once current->seccomp.mode is non-zero, it may not be changed. + * + * Returns 0 on success or -EINVAL on failure. + */ +static long seccomp_set_mode_filter(char __user *filter) +{ + const unsigned long seccomp_mode = SECCOMP_MODE_FILTER; + long ret = -EINVAL; + + if (!seccomp_may_assign_mode(seccomp_mode)) + goto out; + + ret = seccomp_attach_user_filter(filter); + if (ret) goto out; - } seccomp_assign_mode(seccomp_mode); out: return ret; } +#else +static inline long seccomp_set_mode_filter(char __user *filter) +{ + return -EINVAL; +} +#endif /** * prctl_set_seccomp: configures current->seccomp.mode @@ -541,5 +559,12 @@ out: */ long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter) { - return seccomp_set_mode(seccomp_mode, filter); + switch (seccomp_mode) { + case SECCOMP_MODE_STRICT: + return seccomp_set_mode_strict(); + case SECCOMP_MODE_FILTER: + return seccomp_set_mode_filter(filter); + default: + return -EINVAL; + } }