From patchwork Fri Jun 30 03:17:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Xu X-Patchwork-Id: 13297537 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68864EB64D9 for ; Fri, 30 Jun 2023 03:17:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230447AbjF3DRi (ORCPT ); Thu, 29 Jun 2023 23:17:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231653AbjF3DRb (ORCPT ); Thu, 29 Jun 2023 23:17:31 -0400 Received: from mail-ot1-x32f.google.com (mail-ot1-x32f.google.com [IPv6:2607:f8b0:4864:20::32f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 489773594 for ; Thu, 29 Jun 2023 20:17:30 -0700 (PDT) Received: by mail-ot1-x32f.google.com with SMTP id 46e09a7af769-6b71cdb47e1so1151103a34.2 for ; Thu, 29 Jun 2023 20:17:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1688095049; x=1690687049; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=53ZMdGhNmZ+BOpMUbgSFLyEDTkK0ZHteXsorexZvGcc=; b=Hhds97GUYBeppbOwT50AZutzB1nVVfNLRInAfnNP58IkESH6yufdJYjjXoko1dy9G+ 7Ur8NWUwfJrbcpQSpTt286069+coFcb6LHT+Hpu/39T4cIbHcx3ohwZzEN7MljiB4mGX nGNyBGTlMBhsV2p04QbZotAIplV3r6a4qLE4w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688095049; x=1690687049; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=53ZMdGhNmZ+BOpMUbgSFLyEDTkK0ZHteXsorexZvGcc=; b=e/rkhZh07db18ucJ/3gwiYARuTlqarB7MvYprPGaK82OX+W9AA3DMYSyCw9Qa6+1mG qr7RrywrtqDOBGspWD0HSEw8po6FXSMRu8zadeDfOJhyv7zDSLLjvHeWZvFs5VTFzWdH pm8F4kok8VPFxTzCSPkWAQfTqkNkFtf9o35TlIMvWWQOOxaoxVj3ZFESwUZj55qbqy+n Ts2lLWmzlGrCcAT/qjCDaTbFKcjVhfd92BaXfBmw//fD4PVwXNuwfvOqkNaSPjCU8xUY 4Ubb3z6FOZgYtRHyxikP8GQ9DD11tl+CF2o5ERO48pIRDa0A8cg0A4vR6aRdmOOfsNwm 9x8A== X-Gm-Message-State: AC+VfDxwAT8GpR/hZhWBZJguwq7ouA6kdBJvSzUnrbksvS2LRMCYxAB7 pFsT8wYTeMzxGceC61cdHTpm4Q== X-Google-Smtp-Source: ACHHUZ7w0MIcW5kZcKcCzQ5+ZTjH6ysBlmgQ4PxTyUtw8h8Kk3p3zrfxkxjd+Odq2hqr4KUnUW6Icw== X-Received: by 2002:a05:6808:1921:b0:3a3:7e8f:2f2a with SMTP id bf33-20020a056808192100b003a37e8f2f2amr1773186oib.11.1688095049673; Thu, 29 Jun 2023 20:17:29 -0700 (PDT) Received: from localhost (183.43.230.35.bc.googleusercontent.com. [35.230.43.183]) by smtp.gmail.com with UTF8SMTPSA id x24-20020aa784d8000000b0065438394fa4sm1622577pfn.90.2023.06.29.20.17.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 29 Jun 2023 20:17:29 -0700 (PDT) From: jeffxu@chromium.org To: skhan@linuxfoundation.org, keescook@chromium.org Cc: akpm@linux-foundation.org, dmitry.torokhov@gmail.com, dverkamp@chromium.org, asmadeus@codewreck.org, hughd@google.com, jeffxu@google.com, jorgelo@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, jannh@google.com, linux-hardening@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v1 1/2] mm/memfd: sysctl: fix MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED Date: Fri, 30 Jun 2023 03:17:19 +0000 Message-ID: <20230630031721.623955-2-jeffxu@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog In-Reply-To: <20230630031721.623955-1-jeffxu@google.com> References: <20230630031721.623955-1-jeffxu@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org From: Jeff Xu When vm.memfd_noexec is 2 (MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED), memfd_create(.., MFD_EXEC) should fail. This complies with how MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED is defined - "memfd_create() without MFD_NOEXEC_SEAL will be rejected" Link:https://lore.kernel.org/linux-mm/CABi2SkXUX_QqTQ10Yx9bBUGpN1wByOi_=gZU6WEy5a8MaQY3Jw@mail.gmail.com/T/ Fixes: 105ff5339f49 ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC") Reported-by: Dominique Martinet Signed-off-by: Jeff Xu --- mm/memfd.c | 48 +++++++++++++++++++++++++----------------------- 1 file changed, 25 insertions(+), 23 deletions(-) diff --git a/mm/memfd.c b/mm/memfd.c index e763e76f1106..812750298e8a 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -268,6 +268,19 @@ long memfd_fcntl(struct file *file, unsigned int cmd, unsigned int arg) #define MFD_ALL_FLAGS (MFD_CLOEXEC | MFD_ALLOW_SEALING | MFD_HUGETLB | MFD_NOEXEC_SEAL | MFD_EXEC) +static int sysctl_memfd_noexec(void) +{ + int sysctl = MEMFD_NOEXEC_SCOPE_EXEC; +#ifdef CONFIG_SYSCTL + struct pid_namespace *ns; + + ns = task_active_pid_ns(current); + if (ns) + sysctl = ns->memfd_noexec_scope; +#endif + return sysctl; +} + SYSCALL_DEFINE2(memfd_create, const char __user *, uname, unsigned int, flags) @@ -278,6 +291,7 @@ SYSCALL_DEFINE2(memfd_create, int fd, error; char *name; long len; + int sysctl = sysctl_memfd_noexec(); if (!(flags & MFD_HUGETLB)) { if (flags & ~(unsigned int)MFD_ALL_FLAGS) @@ -294,35 +308,23 @@ SYSCALL_DEFINE2(memfd_create, return -EINVAL; if (!(flags & (MFD_EXEC | MFD_NOEXEC_SEAL))) { -#ifdef CONFIG_SYSCTL - int sysctl = MEMFD_NOEXEC_SCOPE_EXEC; - struct pid_namespace *ns; - - ns = task_active_pid_ns(current); - if (ns) - sysctl = ns->memfd_noexec_scope; - - switch (sysctl) { - case MEMFD_NOEXEC_SCOPE_EXEC: - flags |= MFD_EXEC; - break; - case MEMFD_NOEXEC_SCOPE_NOEXEC_SEAL: + if (sysctl == MEMFD_NOEXEC_SCOPE_NOEXEC_SEAL) flags |= MFD_NOEXEC_SEAL; - break; - default: - pr_warn_once( - "memfd_create(): MFD_NOEXEC_SEAL is enforced, pid=%d '%s'\n", - task_pid_nr(current), get_task_comm(comm, current)); - return -EINVAL; - } -#else - flags |= MFD_EXEC; -#endif + else + flags |= MFD_EXEC; + pr_warn_once( "memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=%d '%s'\n", task_pid_nr(current), get_task_comm(comm, current)); } + if (flags & MFD_EXEC && sysctl >= MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED) { + pr_warn_once( + "memfd_create(): MFD_NOEXEC_SEAL is enforced, pid=%d '%s'\n", + task_pid_nr(current), get_task_comm(comm, current)); + return -EACCES; + } + /* length includes terminating zero */ len = strnlen_user(uname, MFD_NAME_MAX_LEN + 1); if (len <= 0) From patchwork Fri Jun 30 03:17:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Xu X-Patchwork-Id: 13297538 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0073C001DB for ; Fri, 30 Jun 2023 03:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231937AbjF3DRj (ORCPT ); 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[35.230.43.183]) by smtp.gmail.com with UTF8SMTPSA id y12-20020a655b4c000000b0055adf339c35sm6407088pgr.31.2023.06.29.20.17.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 29 Jun 2023 20:17:32 -0700 (PDT) From: jeffxu@chromium.org To: skhan@linuxfoundation.org, keescook@chromium.org Cc: akpm@linux-foundation.org, dmitry.torokhov@gmail.com, dverkamp@chromium.org, asmadeus@codewreck.org, hughd@google.com, jeffxu@google.com, jorgelo@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, jannh@google.com, linux-hardening@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v1 2/2] selftests/memfd: sysctl: fix MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED Date: Fri, 30 Jun 2023 03:17:20 +0000 Message-ID: <20230630031721.623955-3-jeffxu@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog In-Reply-To: <20230630031721.623955-1-jeffxu@google.com> References: <20230630031721.623955-1-jeffxu@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org From: Jeff Xu Add selftest for sysctl vm.memfd_noexec is 2 (MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED) memfd_create(.., MFD_EXEC) should fail in this case. Signed-off-by: Jeff Xu --- tools/testing/selftests/memfd/memfd_test.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c index dba0e8ba002f..dbdd9ec5e397 100644 --- a/tools/testing/selftests/memfd/memfd_test.c +++ b/tools/testing/selftests/memfd/memfd_test.c @@ -1147,6 +1147,11 @@ static void test_sysctl_child(void) sysctl_assert_write("2"); mfd_fail_new("kern_memfd_sysctl_2", MFD_CLOEXEC | MFD_ALLOW_SEALING); + mfd_fail_new("kern_memfd_sysctl_2_MFD_EXEC", + MFD_CLOEXEC | MFD_EXEC); + fd = mfd_assert_new("", 0, MFD_NOEXEC_SEAL); + close(fd); + sysctl_fail_write("0"); sysctl_fail_write("1"); }