From patchwork Wed Aug 18 06:05:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 499579 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D931C432BE for ; Wed, 18 Aug 2021 06:25:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07BB260FA0 for ; Wed, 18 Aug 2021 06:25:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240410AbhHRGZ0 (ORCPT ); Wed, 18 Aug 2021 02:25:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239145AbhHRGYz (ORCPT ); Wed, 18 Aug 2021 02:24:55 -0400 Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16F6AC0613CF for ; Tue, 17 Aug 2021 23:24:18 -0700 (PDT) Received: by mail-pg1-x531.google.com with SMTP id 17so1183793pgp.4 for ; Tue, 17 Aug 2021 23:24:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=dkCK961ZyttB0QG+MUzGRc9GbPNZyJOzxDRl3nXU6Gc=; b=F3ghc0DUnRIAuSynTOo4HhTisr9dY2clGPt7Tp2ELGFpLUMoqQjF17RYWes7eco0Fp HKzP4hJH6W8dElSRC/l4MPe4WbDo+9mFg+K8Li9eyi19QvOkLGzu4axj3QbMT/3x3/oK 4mFZNJ8jfnCy22ecNEUEUkyyEwRPO3Ye/ohuI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=dkCK961ZyttB0QG+MUzGRc9GbPNZyJOzxDRl3nXU6Gc=; b=uly7jNCtUq+kUa0Nj6+Npne8ghapgW43UYo7asK3lJCQmbhe2/N28h/fmqkr5nncPo K61WD15FiHSqRukuo4/ZrgeNE2lEAQqYl0R0Rs+sgLu0aIrzCxazKt7wFf82xwMbK+/1 ekcnHVQOd5e3noK4CtEnCdSpxp/wr6fk0Hjgg9N2DL/vPlxaI8ct2pGAZ5LjZ04qUA55 LmWoMtTKf3m7CZou7moImQ5PO2y1H19JVaKkvVcrJn/p/SKWi3sg5/+Rk+ZeLA3kXEr9 svcOlgvF6EosFzsX6UE03BWIkcZ8Hp1qhMNSf+KVuYvlakaep4RRTuMcWMnglQVzjLjv 7t3A== X-Gm-Message-State: AOAM533ktgk0W5zNRUxhdjmRc5foYImK6DOIT3jIeselOxmCloH9VxQ0 B6ci/e2cnz/wTxfz3J/FeAb4ew== X-Google-Smtp-Source: ABdhPJzB6Fpw5lksE03mTikq/l8Ungtb52rwsKcOwzebsF0lTq2QR4kdwv8iqtPBdlFbyxw6WcuEBA== X-Received: by 2002:aa7:8c19:0:b0:3e1:4b9e:cf89 with SMTP id c25-20020aa78c19000000b003e14b9ecf89mr7683859pfd.58.1629267857641; Tue, 17 Aug 2021 23:24:17 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t18sm4582599pfg.111.2021.08.17.23.24.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Aug 2021 23:24:15 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Christophe Leroy , Sudeep Holla , linuxppc-dev@lists.ozlabs.org, kernel test robot , "Gustavo A. R. Silva" , Greg Kroah-Hartman , Andrew Morton , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-staging@lists.linux.dev, linux-block@vger.kernel.org, linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com, Rasmus Villemoes , linux-hardening@vger.kernel.org Subject: [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs Date: Tue, 17 Aug 2021 23:05:27 -0700 Message-Id: <20210818060533.3569517-58-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210818060533.3569517-1-keescook@chromium.org> References: <20210818060533.3569517-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2908; h=from:subject; bh=uD1y/xoxNTfC/kMxy1YHPqDr4W4r5gvR6/3LUb/d/+Q=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBhHKMqjnaaYE2W2OottJ48+Kv314H+c4/L+2RqMHXv r7V1BciJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYRyjKgAKCRCJcvTf3G3AJgmYD/ 4xOx64rrId3koq1dIVBd1c7qtDRXBXq8ocvbv6TiAzQ5OW2IJsAcesmEDGB0aarLTux96zhVYvPuEY ekfg39GKhCgEPeb5jXP+UH57m9qopfeReANE1S4LvEsOJWuHGa5N2yh0MVFMYdstmPHkfTVtOzOdnW 4FpfS36c3/G650GjYZjHYGK93aUv37ocoMf05CH9DSjWcOrGk+21jowTwXALShjZMmIjz5FWSiAPe+ +1eUzjLiqUeJOGZ7Lv40/p3giVTD2/7lEzVVufOf7KMLHvSJmrltr2bLt88CSW+0Qs2cDc8kDwit4g NSusBANylY1K/6uJsrHXOzr8UYkdtB6bsttgeE9V1+wOYhLMeNib3XArxbwXJKppaNHkpLdAyqOc1N hNWxNmFkEb7gLQI+lgaRv2CySpbhIO+o8h7UWzfZ9W2P7Sz8/0+TLD68DRwxBbPxMHy7FpShanbdlR HAvsXrcU8SaCn8kjeuW7pbNPk+pnaYiQiMH5cl3iCfgq1I13gvGVNmMUEdqsNskPE6H1JjH3DkRQLj i7n33M3844UZk+msL24HAJukYQmiAtXqJDGZb3S179NpLnEREMRQveIz0XRN96WDiRCpbvwy644xQe qmxn1RnVllos5p0W46DDS5Z/a2ezsgCPxronRiihYw6gD81m/cUYTrPKHDSw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Add a struct_group() for the spe registers so that memset() can correctly reason about the size: In function 'fortify_memset_chk', inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3: >> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 195 | __write_overflow_field(); | ^~~~~~~~~~~~~~~~~~~~~~~~ Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Christophe Leroy Cc: Sudeep Holla Cc: linuxppc-dev@lists.ozlabs.org Reported-by: kernel test robot Signed-off-by: Kees Cook --- arch/powerpc/include/asm/processor.h | 6 ++++-- arch/powerpc/kernel/signal_32.c | 6 +++--- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index f348e564f7dd..05dc567cb9a8 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -191,8 +191,10 @@ struct thread_struct { int used_vsr; /* set if process has used VSX */ #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE - unsigned long evr[32]; /* upper 32-bits of SPE regs */ - u64 acc; /* Accumulator */ + struct_group(spe, + unsigned long evr[32]; /* upper 32-bits of SPE regs */ + u64 acc; /* Accumulator */ + ); unsigned long spefscr; /* SPE & eFP status */ unsigned long spefscr_last; /* SPEFSCR value on last prctl call or trap return */ diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 0608581967f0..77b86caf5c51 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs, regs_set_return_msr(regs, regs->msr & ~MSR_SPE); if (msr & MSR_SPE) { /* restore spe registers from the stack */ - unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs, - ELF_NEVRREG * sizeof(u32), failed); + unsafe_copy_from_user(¤t->thread.spe, &sr->mc_vregs, + sizeof(current->thread.spe), failed); current->thread.used_spe = true; } else if (current->thread.used_spe) - memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32)); + memset(¤t->thread.spe, 0, sizeof(current->thread.spe)); /* Always get SPEFSCR back */ unsafe_get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed);