From patchwork Sat Apr 20 00:15:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prakhar Srivastava X-Patchwork-Id: 10909877 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 259EC14DB for ; Sat, 20 Apr 2019 00:15:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1481228CBB for ; Sat, 20 Apr 2019 00:15:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 082C728CD7; Sat, 20 Apr 2019 00:15:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8808128CBB for ; Sat, 20 Apr 2019 00:15:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725858AbfDTAPx (ORCPT ); Fri, 19 Apr 2019 20:15:53 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:43128 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727385AbfDTAPx (ORCPT ); Fri, 19 Apr 2019 20:15:53 -0400 Received: by mail-pl1-f193.google.com with SMTP id n8so3208101plp.10; Fri, 19 Apr 2019 17:15:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=89tWsU/OT5SYrbjwn65xtN7OxFoXBZMgUvk/yoALgYk=; b=caxaNmAr98e1Z07q/VdVXR2cdbkxvt0ij/qD+nz6st0OJIM66GbQdII6QNhy2G683g GcefLJltQFAWVCX+J1EkWLoC9k9fG2YB04sREBg51JY6Q172mvr7kRMf9e63J6ijHm5O mLAFGvTIJ71j/q5mFEM89+wuPyMfIJm2qZAzLo6pvBlxm4+u/ycM7/vWLqzPpUmbpKyG 4+4utrKZxBxIx8se+azpuwQ/U4+K3qdXbRHYsNijuRNIcI7qNCObPlQhjEoWyYpOBMLy /ZdTWacRBSYVJbWQrVAwF4Zf8sPQBFM2DQ2Uk/YFDInx1WnWhCMcScnCkGleN2PQXcT5 4mtg== 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; bh=89tWsU/OT5SYrbjwn65xtN7OxFoXBZMgUvk/yoALgYk=; b=Y7kAMaLNyPebPHI0BgJDZuCAhi9ovbktER1uZtbXPtapW+Fu1NRFxBqsoDmcqku/Jc cqOH2+Y+xN3AZvlasm4GO/Hcs+U4fuc97LuhqnCJ8MCFpHmTIuIplZa9yKjai62u/llC QGJVzuJi2d8suae5CwoVE49TTw6Ly5kPL4mgxzMFMhOsGIBmwQMIoHiGH6SpT2RVM6Xi MlnBq7GZo0rInkeR7sBOdCczoVzJlAmWxF2L3ujoF+Zs15E9+MSyWFcgpzQqJyjgNQKs eNASMRimO+fsziYkbW/8PwJQGFGGRG3WLCY+tZvoU1LTyZjb9zJvD6GpgEYFyxwzg+G1 g7jA== X-Gm-Message-State: APjAAAU1a0SLRbTKYPk6LxuAbKwWhCbbZW3014EQ/YOxaLs9P5KvVNwg XsT4VPSaUuPsCdDoE9WWtsjEZGDpj1E= X-Google-Smtp-Source: APXvYqyTxq2Z5dU4I+e4VPdnoXkBsRm6nfrvXB314dNiWiHFwvVNPMKMA8xHlPMfe5wK+uMnS5XiJA== X-Received: by 2002:a17:902:ea8d:: with SMTP id cv13mr65059plb.23.1555719352046; Fri, 19 Apr 2019 17:15:52 -0700 (PDT) Received: from prsriva-linux.corp.microsoft.com ([2001:4898:80e8:2:5828:72bc:96ef:ce7c]) by smtp.gmail.com with ESMTPSA id a3sm8339902pfn.182.2019.04.19.17.15.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 19 Apr 2019 17:15:51 -0700 (PDT) From: Prakhar Srivastava X-Google-Original-From: Prakhar Srivastava To: linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org Cc: zohar@linux.vnet.ibm.com, ebiederm@xmission.com, vgoyal@redhat.com, Prakhar Srivastava , Prakhar Srivastava Subject: [PATCH v2 3/3 RFC] since cmdline args can be same for multiple kexec, log entry hash will collide. Prepend the kernel file name to the cmdline args to distinguish between cmdline args passed to subsequent kexec calls Date: Fri, 19 Apr 2019 17:15:43 -0700 Message-Id: <20190420001543.6760-3-prsriva02@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190420001543.6760-1-prsriva02@gmail.com> References: <20190420001543.6760-1-prsriva02@gmail.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Prakhar Srivastava Signed-off-by: Prakhar Srivastava --- Currently for soft reboot(kexec_file_load) the kernel file and signature is measured by IMA. The cmdline args used to load the kernel is not measured. The boot aggregate that gets calculated will have no change since the EFI loader has not been triggered. Adding the kexec cmdline args measure and kernel version will add some attestable criteria. Cmdline args can be same for multiple kexec, log entry hash will collide. Prepend the kernel file name to the cmdline args to distinguish between cmdline args passed to subsequent kexec calls kernel/kexec_core.c | 57 +++++++++++++++++++++++++++++++++++++++++ kernel/kexec_file.c | 14 ++++++++-- kernel/kexec_internal.h | 3 +++ 3 files changed, 72 insertions(+), 2 deletions(-) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index ae1a3ba24df5..97b77c780311 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -1151,3 +1151,60 @@ void __weak arch_kexec_protect_crashkres(void) void __weak arch_kexec_unprotect_crashkres(void) {} + +/** + * kexec_cmdline_prepend_img_name - prepare the buffer with cmdline + * that needs to be measured + * @outbuf - out buffer that contains the formated string + * @kernel_fd - the file identifier for the kerenel image + * @cmdline_ptr - ptr to the cmdline buffer + * @cmdline_len - len of the buffer. + * + * This generates a buffer in the format Kerenelfilename::cmdline + * + * On success return 0. + * On failure return -EINVAL. + */ +int kexec_cmdline_prepend_img_name(char **outbuf, int kernel_fd, + const char *cmdline_ptr, + unsigned long cmdline_len) +{ + int ret = -EINVAL; + struct fd f = {}; + int size = 0; + char *buf = NULL; + char delimiter[] = "::"; + + if (!outbuf || !cmdline_ptr) + goto out; + + f = fdget(kernel_fd); + if (!f.file) + goto out; + + size = (f.file->f_path.dentry->d_name.len + cmdline_len - 1+ + ARRAY_SIZE(delimiter)) - 1; + + buf = kzalloc(size, GFP_KERNEL); + if (!buf) + goto out; + + memcpy(buf, f.file->f_path.dentry->d_name.name, + f.file->f_path.dentry->d_name.len); + memcpy(buf + f.file->f_path.dentry->d_name.len, + delimiter, ARRAY_SIZE(delimiter) - 1); + memcpy(buf + f.file->f_path.dentry->d_name.len + + ARRAY_SIZE(delimiter) - 1, + cmdline_ptr, cmdline_len - 1); + + *outbuf = buf; + ret = size; + + pr_debug("kexec cmdline buff: %s\n", buf); + +out: + if (f.file) + fdput(f); + + return ret; +} diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 2a5234eb4b28..a487491d55b9 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -126,6 +126,8 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, int ret = 0; void *ldata; loff_t size; + char *buff_to_measure = NULL; + int buff_to_measure_size = 0; ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf, &size, INT_MAX, READING_KEXEC_IMAGE); @@ -183,8 +185,13 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, goto out; } - ima_buffer_check(image->cmdline_buf, cmdline_len - 1, - "kexec_cmdline"); + /* IMA measures the cmdline args passed to the next kernel*/ + buff_to_measure_size = kexec_cmdline_prepend_img_name(&buff_to_measure, + kernel_fd, image->cmdline_buf, image->cmdline_buf_len); + + ima_buffer_check(buff_to_measure, buff_to_measure_size, + "kexec_cmdline"); + } /* Call arch image load handlers */ @@ -200,6 +207,9 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, /* In case of error, free up all allocated memory in this function */ if (ret) kimage_file_post_load_cleanup(image); + + kfree(buff_to_measure); + return ret; } diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h index 799a8a452187..4d34a8ef4637 100644 --- a/kernel/kexec_internal.h +++ b/kernel/kexec_internal.h @@ -11,6 +11,9 @@ int kimage_load_segment(struct kimage *image, struct kexec_segment *segment); void kimage_terminate(struct kimage *image); int kimage_is_destination_range(struct kimage *image, unsigned long start, unsigned long end); +int kexec_cmdline_prepend_img_name(char **outbuf, int kernel_fd, + const char *cmdline_ptr, + unsigned long cmdline_len); extern struct mutex kexec_mutex;