From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A80DE1CF8B for ; Fri, 18 Apr 2025 04:33:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744950821; cv=none; b=tF/Z+O/EQq558sUJF3ICotz7BHnMdGbljgAFMSa01NR75O6CYFo+HuJoZXrFs9IGgUnHOPEykbEZ9ZIkGlRV5ss3pHHwTDGykJw3tvWKq+nLpmyD2WCvKXbblRYNrlvvBcbrjs5tC9TOLPz3Aq3jUTZ5pyxfAvEaZgWd26kOj0E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744950821; c=relaxed/simple; bh=LTUP2n/LOQ1CRKDOZOzdgkRQ30gJSVxW7Fz61LvJM7I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fz4BFq9JWM7rSEOM/H6JZUCQi2SWrRycqsAp0e6QiFFfOzm2d2DK85tbgW3sAVBA8cPbTqBpeGafGqbWWCXhoufG3RaZdFKLF3kdGm0yQjV97pfF+/gHDaVnKtccofCswa9eX1HbkNQn7fyJiwNzAKckqbVIzIDx5zXFLooODBE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=RoNZQ6Yd; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RoNZQ6Yd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744950817; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=g3F5hBYyFCUjuYWeqvOWU5reA4YYpl84M01/MAUamts=; b=RoNZQ6YdFyb7Oj+2VEWteJFbAuzFXb2qjH3iZT/zu8v+/h/6vCoy4LTeqesrkWmP+d5f8z 1BIA9i8F2XXC85qmnqjL/B3hcc25uK8BtVzr5/r2q3eRmaFVT8M/0ggBF4kNPq52TOswDF nxVBDlNxs70ku0+D0w/8HPjrO/trGn4= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-548-nLnjpkB-MiCB15MIqwLSWg-1; Fri, 18 Apr 2025 00:33:35 -0400 X-MC-Unique: nLnjpkB-MiCB15MIqwLSWg-1 X-Mimecast-MFC-AGG-ID: nLnjpkB-MiCB15MIqwLSWg_1744950813 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 68132180048E; Fri, 18 Apr 2025 04:33:32 +0000 (UTC) Received: from localhost (unknown [10.72.112.106]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 19ACE19560A3; Fri, 18 Apr 2025 04:33:29 +0000 (UTC) Date: Fri, 18 Apr 2025 12:33:26 +0800 From: Baoquan He To: steven chen Cc: 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, madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@hansenpartnership.com, vgoyal@redhat.com, dyoung@redhat.com Subject: Re: [PATCH v12 2/9] ima: define and call ima_alloc_kexec_file_buf() Message-ID: References: <20250416021028.1403-1-chenste@linux.microsoft.com> <20250416021028.1403-3-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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250416021028.1403-3-chenste@linux.microsoft.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Hi Steven, On 04/15/25 at 07:10pm, steven chen wrote: > From: Steven Chen > > In the current implementation, the ima_dump_measurement_list() API is > called during the kexec "load" phase, where a buffer is allocated and > 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'. Seems you didn't add note in this patch log to mention that the IMA measurement list fails to verify when doing two consecuritv "kexec -s -l" with/without a "kexec -s -u" in between. When people do bisecting and come to this patch, she/he will see the failure even though it's not a fatal blocker. ==== 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 IMA log copy from kexec load to execute" the IMA measurement list verifies properly with the vfree() here. ==== > > Signed-off-by: Tushar Sugandhi > Signed-off-by: Steven Chen > --- > 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/ima_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" > > #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 = NULL; > + sf->size = 0; > + sf->read_pos = 0; > + sf->count = 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 = vmalloc(segment_size); > + if (!ima_kexec_file.buf) > + return -ENOMEM; > + > + ima_kexec_file.size = segment_size; > + ima_kexec_file.read_pos = 0; > + ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ > + > + return 0; > +} > + > static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > unsigned long segment_size) > { > - struct seq_file ima_kexec_file; > struct ima_queue_entry *qe; > struct ima_kexec_hdr khdr; > int ret = 0; > > /* segment size can't change between kexec load and execute */ > - ima_kexec_file.buf = vmalloc(segment_size); > if (!ima_kexec_file.buf) { > - ret = -ENOMEM; > - goto out; > + pr_err("Kexec file buf not allocated\n"); > + return -EINVAL; > } > > - ima_kexec_file.file = NULL; > - ima_kexec_file.size = segment_size; > - ima_kexec_file.read_pos = 0; > - ima_kexec_file.count = sizeof(khdr); /* reserved space */ > - > memset(&khdr, 0, sizeof(khdr)); > khdr.version = 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 *buffer_size, void **buffer, > *buffer_size = ima_kexec_file.count; > *buffer = ima_kexec_file.buf; > out: > - if (ret == -EINVAL) > - vfree(ima_kexec_file.buf); > return ret; > } > > @@ -111,6 +129,12 @@ void ima_add_kexec_buffer(struct kimage *image) > return; > } > > + ret = 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) { > -- > 2.43.0 >