From patchwork Wed Feb 14 15:38:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 13556704 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 286445D467 for ; Wed, 14 Feb 2024 15:38:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707925118; cv=none; b=ngCmj1fOnBEWxNBRo6WPX0Qn6epyfSHWAw/NgK8RP5YpKMdYXzvMcpe+Uq7fNb0RbxILMxE4JsPQ2JPm2mAy3ts5ijDMLaeXe3DVFV4ILdzdEa+jA/G06spQdTVNXFIRj1931hB7FM/QDHX4plGj3Gz9Fq7+E7DyPRdps4xqnic= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707925118; c=relaxed/simple; bh=2FUau0fiARE/5o6MdioIQEDQ2ej6OVBys6g2KKA9RZ4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Q44cio9wk2Bq4BFL4TtC2UD+giQUoBhuNiDUxX7uJA4jdlBTrqinkHLsi0IKwKt1tDLs+7tCO8/yy6X8J/7tx2gjONZdUYhkPKZlZs1n2xMYs1ebMrcfEdTKN8WzkvESNyRWf1e4/MdvzysBwCughEDxJC2/9/0am/jsegFsbww= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=X36gxMzU; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="X36gxMzU" Received: from tushar-HP-Pavilion-Laptop-15-eg0xxx.lan (unknown [50.46.228.62]) by linux.microsoft.com (Postfix) with ESMTPSA id BF2F120B2005; Wed, 14 Feb 2024 07:38:35 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com BF2F120B2005 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1707925115; bh=ZlIccf7Ox9/YKL2es1yXhbAiKARAN1cP73a//eRxN5g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X36gxMzUPc70JtXNRuKZiHxPx50rW99EylvQtZD3RWl+bRX+tsTbjn+LjZ7HUbx0G xhBnsOojVkxrp3OgqaL9nXPxm8cK1wvt4lqGA6+q02kR3zucWoOOn8sUqW+cHQQ+Ji 2yji3N+cGifW/1Y+syvRgjjsR1pm7SpdSbdZiKZU= From: Tushar Sugandhi To: zohar@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, stefanb@linux.ibm.com, ebiederm@xmission.com, noodles@fb.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com Subject: [PATCH v5 5/8] ima: kexec: move IMA log copy from kexec load to execute Date: Wed, 14 Feb 2024 07:38:24 -0800 Message-Id: <20240214153827.1087657-6-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240214153827.1087657-1-tusharsu@linux.microsoft.com> References: <20240214153827.1087657-1-tusharsu@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 ima_dump_measurement_list() is called during kexec 'load', which may result in loss of IMA measurements during kexec soft reboot. It needs to be called during kexec 'execute'. This patch includes the following changes: - Call kimage_file_post_load() from kexec_file_load() syscall only for kexec soft reboot scenarios and not for KEXEC_FILE_ON_CRASH. It will map the IMA segment, and register reboot notifier for the function ima_update_kexec_buffer() which would copy the IMA log at kexec soft reboot. - Make kexec_segment_size variable local static to the file, for it to be accessible both during kexec 'load' and 'execute'. - Move ima_dump_measurement_list() call from ima_add_kexec_buffer() to ima_update_kexec_buffer(). - Remove ima_reset_kexec_file() call from ima_add_kexec_buffer(), now that the buffer is being copied at kexec 'execute', and resetting the file at kexec 'load' will corrupt the buffer. Signed-off-by: Tushar Sugandhi --- kernel/kexec_file.c | 3 ++ security/integrity/ima/ima_kexec.c | 45 +++++++++++++++++++----------- 2 files changed, 32 insertions(+), 16 deletions(-) diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index fe59cb7c179d..2d5df320c34f 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -410,6 +410,9 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, kimage_terminate(image); + if (!(flags & KEXEC_FILE_ON_CRASH)) + kimage_file_post_load(image); + ret = machine_kexec_post_load(image); if (ret) goto out; diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 1d4d6c122d82..98fc9b9782a2 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -19,6 +19,7 @@ #ifdef CONFIG_IMA_KEXEC static struct seq_file ima_kexec_file; static void *ima_kexec_buffer; +static size_t kexec_segment_size; static bool ima_kexec_update_registered; static void ima_reset_kexec_file(struct seq_file *sf) @@ -129,7 +130,6 @@ void ima_add_kexec_buffer(struct kimage *image) /* use more understandable variable names than defined in kbuf */ void *kexec_buffer = NULL; size_t kexec_buffer_size; - size_t kexec_segment_size; int ret; /* @@ -154,14 +154,6 @@ void ima_add_kexec_buffer(struct kimage *image) return; } - ret = ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, - kexec_segment_size); - if (ret < 0) { - pr_err("%s: Failed to dump IMA measurements. Error:%d.\n", - __func__, ret); - return; - } - kbuf.buffer = kexec_buffer; kbuf.bufsz = kexec_buffer_size; kbuf.memsz = kexec_segment_size; @@ -179,12 +171,6 @@ void ima_add_kexec_buffer(struct kimage *image) image->ima_segment_index = image->nr_segments - 1; image->is_ima_segment_index_set = true; - /* - * kexec owns kexec_buffer after kexec_add_buffer() is called - * and it will vfree() that buffer. - */ - ima_reset_kexec_file(&ima_kexec_file); - kexec_dprintk("kexec measurement buffer for the loaded kernel at 0x%lx.\n", kbuf.mem); } @@ -195,7 +181,34 @@ void ima_add_kexec_buffer(struct kimage *image) static int ima_update_kexec_buffer(struct notifier_block *self, unsigned long action, void *data) { - return NOTIFY_OK; + void *buf = NULL; + size_t buf_size; + int ret = NOTIFY_OK; + + if (!kexec_in_progress) { + pr_info("%s: No kexec in progress.\n", __func__); + return ret; + } + + if (!ima_kexec_buffer) { + pr_err("%s: Kexec buffer not set.\n", __func__); + return ret; + } + + ret = ima_dump_measurement_list(&buf_size, &buf, + kexec_segment_size); + + if (!buf) { + pr_err("%s: Dump measurements failed. Error:%d\n", + __func__, ret); + goto out; + } + memcpy(ima_kexec_buffer, buf, buf_size); +out: + kimage_unmap_segment(ima_kexec_buffer); + ima_kexec_buffer = NULL; + + return ret; } struct notifier_block update_buffer_nb = {