From nobody Thu Dec 18 19:37:55 2025 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4ABE623A9BB; Wed, 2 Apr 2025 12:47:51 +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=1743598072; cv=none; b=At+bhczFbqPqToJV4+Z9809ZeyB+Y+Bz/RwCBpd2/IOBbj/eZ0URBViAQprYDwKFMmVNKQqYrb9lNwcT4vadFl2iPiV/VxOW0Uhr/sXssi1F1vjE3MwlaHE3SPn9XgLB8PgOJU+WB+KsumGhec8EIEQ7ZFHuxwPoE3ChS3DhVe8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743598072; c=relaxed/simple; bh=UJARWayehLsjZgGqf0RmGLlvGyEW1VUvommtCqeX4Sg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HSQyYGzNXqzplFPN8mMq1dhLT3F4hu9IOaTCDb4LazFF9bvcegLTGj+XhmjAzJ9/VHoz1kg2QtBaw1E8unF5YOFZcbx2VCJ2ZLRGNndwIXBzf5oLtq/N0F9/4p9T0bu39/RjASncIYGvAPN7ZmPZgFHlSQ5x6Qw8B6d1nJLSi+s= 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=GtRTizlI; 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="GtRTizlI" Received: from DESKTOP-VOT081N.hsd1.ga.comcast.net (unknown [20.114.144.49]) by linux.microsoft.com (Postfix) with ESMTPSA id D4A412041304; Wed, 2 Apr 2025 05:47:48 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D4A412041304 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1743598070; bh=vEw/LreqQOxRk2U8fSqzR4thwxp7A3QOtHmi4q7KOMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GtRTizlIYLiPu/gEQNWmihR/pySHx3nmYZ4ceLusbrt3hTu79kPiO3ZEhNoVY1l/F gwibjdMU9ojf1gSoope+Up2tNXS+wzmwkZl5KDK/RVzcVpxgFubtvGqdAj7uJUTlh5 r+8O74/ReycP1R6AIAhUH6H4Y3XqLPWUrk+sJlck= From: steven chen To: zohar@linux.ibm.com, stefanb@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, ebiederm@xmission.com, paul@paul-moore.com, code@tyhicks.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Cc: madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@HansenPartnership.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com Subject: [PATCH v11 6/9] ima: kexec: move IMA log copy from kexec load to execute Date: Wed, 2 Apr 2025 05:47:19 -0700 Message-ID: <20250402124725.5601-7-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250402124725.5601-1-chenste@linux.microsoft.com> References: <20250402124725.5601-1-chenste@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" ima_dump_measurement_list() is called during kexec 'load', which may result in loss of IMA measurements during kexec soft reboot. Due to=20 missed measurements that only occurred after kexec 'load', this function=20 needs to be called during kexec 'execute'. Make the kexec_segment_size variable a local static variable within the=20 file, so it can be accessed during both kexec 'load' and 'execute'. =20 Implement the kexec_post_load() function to be invoked after the new kernel image has been loaded for kexec. Instead of calling machine_kexec_post_load= () directly from the kexec_file_load() syscall, call kexec_post_load(), which = in turn calls machine_kexec_post_load() to maintain the original image process= ing. =20 Invoke ima_kexec_post_load() within the kexec_post_load() API only for kexe= c=20 soft reboot scenarios, excluding KEXEC_FILE_ON_CRASH. =20 Register a reboot notifier for the ima_update_kexec_buffer() API within=20 ima_kexec_post_load() to ensure it is called upon receiving a reboot=20 notification. =20 Move the ima_dump_measurement_list() call from ima_add_kexec_buffer() to=20 ima_update_kexec_buffer() to copy the IMA log at the kexec 'execute' stage. =20 When there is insufficient memory to copy all the measurement logs, copy as much of the measurement list as possible. Signed-off-by: Tushar Sugandhi Cc: Eric Biederman Cc: Baoquan He =20 Cc: Vivek Goyal Cc: Dave Young Signed-off-by: steven chen Reviewed-by: Stefan Berger --- kernel/kexec_file.c | 11 +++++++- security/integrity/ima/ima_kexec.c | 43 ++++++++++++++++++++---------- 2 files changed, 39 insertions(+), 15 deletions(-) diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 606132253c79..b3eb515ca051 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -201,6 +201,15 @@ kimage_validate_signature(struct kimage *image) } #endif =20 +static int kexec_post_load(struct kimage *image, unsigned long flags) +{ +#ifdef CONFIG_IMA_KEXEC + if (!(flags & KEXEC_FILE_ON_CRASH)) + ima_kexec_post_load(image); +#endif + return machine_kexec_post_load(image); +} + /* * In file mode list of segments is prepared by kernel. Copy relevant * data from user space, do error checking, prepare segment list @@ -428,7 +437,7 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, i= nitrd_fd, =20 kimage_terminate(image); =20 - ret =3D machine_kexec_post_load(image); + ret =3D kexec_post_load(image, flags); if (ret) goto out; =20 diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/im= a_kexec.c index e79f6caf895b..5c3b3e0b2186 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -19,6 +19,7 @@ #ifdef CONFIG_IMA_KEXEC static bool ima_kexec_update_registered; static struct seq_file ima_kexec_file; +static size_t kexec_segment_size; static void *ima_kexec_buffer; =20 static void ima_free_kexec_file_buf(struct seq_file *sf) @@ -72,9 +73,6 @@ static int ima_dump_measurement_list(unsigned long *buffe= r_size, void **buffer, } } =20 - if (ret < 0) - goto out; - /* * fill in reserved space with some buffer details * (eg. version, buffer size, number of measurements) @@ -94,7 +92,7 @@ static int ima_dump_measurement_list(unsigned long *buffe= r_size, void **buffer, =20 *buffer_size =3D ima_kexec_file.count; *buffer =3D ima_kexec_file.buf; -out: + return ret; } =20 @@ -112,9 +110,8 @@ void ima_add_kexec_buffer(struct kimage *image) unsigned long binary_runtime_size; =20 /* use more understandable variable names than defined in kbuf */ + size_t kexec_buffer_size =3D 0; void *kexec_buffer =3D NULL; - size_t kexec_buffer_size; - size_t kexec_segment_size; int ret; =20 /* @@ -139,13 +136,6 @@ void ima_add_kexec_buffer(struct kimage *image) return; } =20 - ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, - kexec_segment_size); - if (!kexec_buffer) { - pr_err("Not enough memory for the kexec measurement buffer.\n"); - return; - } - kbuf.buffer =3D kexec_buffer; kbuf.bufsz =3D kexec_buffer_size; kbuf.memsz =3D kexec_segment_size; @@ -173,7 +163,32 @@ 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; + size_t buf_size =3D 0; + int ret =3D NOTIFY_OK; + void *buf =3D NULL; + + if (!kexec_in_progress) { + pr_info("No kexec in progress.\n"); + return ret; + } + + if (!ima_kexec_buffer) { + pr_err("Kexec buffer not set.\n"); + return ret; + } + + ret =3D ima_dump_measurement_list(&buf_size, &buf, kexec_segment_size); + + if (ret) + pr_err("Dump measurements failed. Error:%d\n", ret); + + if (buf_size !=3D 0) + memcpy(ima_kexec_buffer, buf, buf_size); + + kimage_unmap_segment(ima_kexec_buffer); + ima_kexec_buffer =3D NULL; + + return ret; } =20 static struct notifier_block update_buffer_nb =3D { --=20 2.25.1