From nobody Fri Dec 19 07:17:40 2025 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3B8CB224AE4; Mon, 21 Apr 2025 22:25:35 +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=1745274336; cv=none; b=JQJjdilnPw6eIcrTj1PPUEHcpJR/Iq1K0ZkdytqljJj/TU0QaXvDXjujugRa9eiak0ztetQhGcbUWIOCUyW8MujU8cAJOR2seVyTiWJAGIgOM27LK7WhCVfP+E5rKEnl3RNDTHBXcuijCh5gq+Cjzqra9IJnW21hVWrkSchCr40= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745274336; c=relaxed/simple; bh=jygzxH5VKpOvsWN0n66rkjiR+sI0RaY1DndvyqxUW9o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rN+J4un8NWSMQRTVp9BngpEPOjBTgZ4v9amfNn9zcRekOBb72MqAHfMiDtZ5AwCL0Fw6kVWjlwuvPcrY5R2wJUFr5pEx+E8YMBLXfR8DJZGnKtMPOWYPK+a2gOaKIOYFY5KW1ZE7WRpZQXU8EeTLbTMWzSVIX2Mu5SEpkJRaJMk= 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=HT+7dbnz; 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="HT+7dbnz" Received: from DESKTOP-VOT081N.hsd1.ga.comcast.net (unknown [20.110.218.7]) by linux.microsoft.com (Postfix) with ESMTPSA id BD21C203B86F; Mon, 21 Apr 2025 15:25:32 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com BD21C203B86F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1745274334; bh=OhLeHH8qkJgkp47mKp8k5q0SWo6uUAk7Wl6ng3yPD2o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HT+7dbnz3dGW/nvbVxve+EscOBwLHpFDM6o92MWsIf1swSqKX34KVpLlGCms0qMNC 7TvGMThJW5ZsCzSD1sif9hL4MeRtC0/+Ldlzrspi0ljIzGneZZdSa0JNX7eJrpw9Is wQWM3Mjqkd8DPkaCf7yqzGDpDKWMUObY+3hoPVsU= 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 v13 2/9] ima: define and call ima_alloc_kexec_file_buf() Date: Mon, 21 Apr 2025 15:25:08 -0700 Message-ID: <20250421222516.9830-3-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250421222516.9830-1-chenste@linux.microsoft.com> References: <20250421222516.9830-1-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" From: Steven Chen In the current implementation, the ima_dump_measurement_list() API is=20 called during the kexec "load" phase, where a buffer is allocated and=20 the measurement records are copied. Due to this, new events added after kexec load but before kexec execute are not carried over to the new kernel during kexec operation Carrying the IMA measurement list across kexec requires allocating a buffer and copying the measurement records. Separate allocating the buffer and copying the measurement records into separate functions in order to allocate the buffer at kexec 'load' and copy the measurements at kexec 'execute'. After moving the vfree() here at this stage in the patch set, the IMA measurement list fails to verify when doing two consecutive "kexec -s -l" with/without a "kexec -s -u" in between. Only after "ima: kexec: move=20 IMA log copy from kexec load to execute" the IMA measurement list verifies properly with the vfree() here. Co-developed-by: Tushar Sugandhi Signed-off-by: Tushar Sugandhi Signed-off-by: Steven Chen Acked-by: Baoquan He Reviewed-by: Stefan Berger --- security/integrity/ima/ima_kexec.c | 46 +++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 11 deletions(-) diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/im= a_kexec.c index 650beb74346c..b12ac3619b8f 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -15,26 +15,46 @@ #include "ima.h" =20 #ifdef CONFIG_IMA_KEXEC +static struct seq_file ima_kexec_file; + +static void ima_free_kexec_file_buf(struct seq_file *sf) +{ + vfree(sf->buf); + sf->buf =3D NULL; + sf->size =3D 0; + sf->read_pos =3D 0; + sf->count =3D 0; +} + +static int ima_alloc_kexec_file_buf(size_t segment_size) +{ + ima_free_kexec_file_buf(&ima_kexec_file); + + /* segment size can't change between kexec load and execute */ + ima_kexec_file.buf =3D vmalloc(segment_size); + if (!ima_kexec_file.buf) + return -ENOMEM; + + ima_kexec_file.size =3D segment_size; + ima_kexec_file.read_pos =3D 0; + ima_kexec_file.count =3D sizeof(struct ima_kexec_hdr); /* reserved space = */ + + return 0; +} + static int ima_dump_measurement_list(unsigned long *buffer_size, void **bu= ffer, unsigned long segment_size) { - struct seq_file ima_kexec_file; struct ima_queue_entry *qe; struct ima_kexec_hdr khdr; int ret =3D 0; =20 /* segment size can't change between kexec load and execute */ - ima_kexec_file.buf =3D vmalloc(segment_size); if (!ima_kexec_file.buf) { - ret =3D -ENOMEM; - goto out; + pr_err("Kexec file buf not allocated\n"); + return -EINVAL; } =20 - ima_kexec_file.file =3D NULL; - ima_kexec_file.size =3D segment_size; - ima_kexec_file.read_pos =3D 0; - ima_kexec_file.count =3D sizeof(khdr); /* reserved space */ - memset(&khdr, 0, sizeof(khdr)); khdr.version =3D 1; /* This is an append-only list, no need to hold the RCU read lock */ @@ -71,8 +91,6 @@ static int ima_dump_measurement_list(unsigned long *buffe= r_size, void **buffer, *buffer_size =3D ima_kexec_file.count; *buffer =3D ima_kexec_file.buf; out: - if (ret =3D=3D -EINVAL) - vfree(ima_kexec_file.buf); return ret; } =20 @@ -111,6 +129,12 @@ void ima_add_kexec_buffer(struct kimage *image) return; } =20 + ret =3D ima_alloc_kexec_file_buf(kexec_segment_size); + if (ret < 0) { + pr_err("Not enough memory for the kexec measurement buffer.\n"); + return; + } + ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, kexec_segment_size); if (!kexec_buffer) { --=20 2.43.0