From patchwork Thu Apr 29 07:20:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Christopher M. Riedl" X-Patchwork-Id: 1471533 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FW6cv1DlNz9sj0 for ; Thu, 29 Apr 2021 17:31:27 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FW6cv0Yznz30Gg for ; Thu, 29 Apr 2021 17:31:27 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=bluescreens.de (client-ip=91.198.250.237; helo=mout-y-209.mailbox.org; envelope-from=cmr@bluescreens.de; receiver=) X-Greylist: delayed 570 seconds by postgrey-1.36 at boromir; Thu, 29 Apr 2021 17:31:10 AEST Received: from mout-y-209.mailbox.org (mout-y-209.mailbox.org [91.198.250.237]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FW6cZ2CmGz2xdQ for ; Thu, 29 Apr 2021 17:31:09 +1000 (AEST) Received: from smtp2.mailbox.org (smtp2.mailbox.org [80.241.60.241]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-y-209.mailbox.org (Postfix) with ESMTPS id 4FW6Pd0dgKzQjnd; Thu, 29 Apr 2021 09:21:41 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp2.mailbox.org ([80.241.60.241]) by spamfilter01.heinlein-hosting.de (spamfilter01.heinlein-hosting.de [80.241.56.115]) (amavisd-new, port 10030) with ESMTP id KhKuAb7f_UxY; Thu, 29 Apr 2021 09:21:38 +0200 (CEST) From: "Christopher M. Riedl" To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 09/11] lkdtm/powerpc: Fix code patching hijack test Date: Thu, 29 Apr 2021 02:20:55 -0500 Message-Id: <20210429072057.8870-10-cmr@bluescreens.de> In-Reply-To: <20210429072057.8870-1-cmr@bluescreens.de> References: <20210429072057.8870-1-cmr@bluescreens.de> MIME-Version: 1.0 X-MBO-SPAM-Probability: * X-Rspamd-Score: 0.57 / 15.00 / 15.00 X-Rspamd-Queue-Id: 3642C17EF X-Rspamd-UID: d1088b X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tglx@linutronix.de, x86@kernel.org, linux-hardening@vger.kernel.org, keescook@chromium.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Code patching on powerpc with a STRICT_KERNEL_RWX uses a userspace address in a temporary mm now. Use __put_user() to avoid write failures due to KUAP when attempting a "hijack" on the patching address. Signed-off-by: Christopher M. Riedl --- drivers/misc/lkdtm/perms.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 55c3bec6d3b72..af9bf285fe326 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -268,16 +268,7 @@ static inline u32 lkdtm_read_patch_site(void) /* Returns True if the write succeeds */ static inline bool lkdtm_try_write(u32 data, u32 *addr) { -#ifdef CONFIG_PPC - __put_kernel_nofault(addr, &data, u32, err); - return true; - -err: - return false; -#endif -#ifdef CONFIG_X86_64 return !__put_user(data, addr); -#endif } static int lkdtm_patching_cpu(void *data)