Re: [PATCH v4 1/1] improve_kernel_cve_report: Add a bbclass support

[Benjamin ROBIN <benjamin.robin@bootlin.com>]

Hello,

Sorry to provide these remarks in the v4 version.

On Monday, January 19, 2026 at 7:40 PM, ValentinBoudevin wrote:
> Signed-off-by: Valentin Boudevin <valentin.boudevin@gmail.com>
> ---
>  .../improve_kernel_cve_report-base.bbclass    | 149 ++++++++++++++++++
>  ...improve_kernel_cve_report-spdx-2.2.bbclass |   4 +
>  .../improve_kernel_cve_report-spdx.bbclass    |   4 +
>  3 files changed, 157 insertions(+)
>  create mode 100644 meta/classes/improve_kernel_cve_report-base.bbclass
>  create mode 100644 meta/classes/improve_kernel_cve_report-spdx-2.2.bbclass
>  create mode 100644 meta/classes/improve_kernel_cve_report-spdx.bbclass
> 
> diff --git a/meta/classes/improve_kernel_cve_report-base.bbclass b/meta/classes/improve_kernel_cve_report-base.bbclass
> new file mode 100644
> index 0000000000..9d3be08203
> --- /dev/null
> +++ b/meta/classes/improve_kernel_cve_report-base.bbclass
> @@ -0,0 +1,149 @@

Maybe add documentation on how to use this bbclass?

> +# Settings for the vulns git repository configuration
> +IMPROVE_KERNEL_CVE_SRC_URI ?= "git://git.kernel.org/pub/scm/linux/security/vulns.git;branch=master;protocol=https"
> +IMPROVE_KERNEL_CVE_SRCREV ?= "${@bb.fetch2.get_autorev(d)}"
> +IMPROVE_KERNEL_CVE_NETWORK ?= "1"
> +IMPROVE_KERNEL_CVE_WORKDIR ?= "${WORKDIR}/vulns"
> +IMPROVE_KERNEL_CVE_DESTSUFFIX ?= "git"
> +IMPROVE_KERNEL_CVE_UNPACK_DIR ?= "${IMPROVE_KERNEL_CVE_WORKDIR}/${IMPROVE_KERNEL_CVE_DESTSUFFIX}"
> +
> +# Settings for SPDX support
> +IMPROVE_KERNEL_PREFERRED_PROVIDER ?= ""
> +IMPROVE_KERNEL_SPDX_FILE ?= ""
> +
> +python __anonymous() {
> +    srcrev = d.getVar("IMPROVE_KERNEL_CVE_SRCREV", True) or ""
> +    network = d.getVar("IMPROVE_KERNEL_CVE_NETWORK", True) or "0"
> +    # Check the IMPROVE_KERNEL_SPDX_FILE variable was set
> +    if not d.getVar("IMPROVE_KERNEL_SPDX_FILE"):
> +        bb.fatal("improve_kernel_cve: IMPROVE_KERNEL_SPDX_FILE is not set. Need to inherit improve_kernel_cve_report-spdx-2.2 or improve_kernel_cve_report-spdx")
> +        return
> +    # Check if networking is enabled to set SRC_URI
> +    if network == "0":
> +        d.appendVar("SRC_URI", " ${IMPROVE_KERNEL_CVE_SRC_URI};name=improve-kernel-cve;destsuffix=${IMPROVE_KERNEL_CVE_DESTSUFFIX}")
> +    # Check offline mode with AUTOREV-like SRCREV
> +    if network == "0" and srcrev.strip() in ("${AUTOREV}", "AUTOINC", "INVALID"):
> +        bb.fatal("improve_kernel_cve: Offline mode but SRCREV is set to AUTOREV/AUTOINC/INVALID. Cannot proceed without network access or use a fixed SRCREV.")
> +    d.setVar("SRCREV_improve-kernel-cve", d.getVar("IMPROVE_KERNEL_CVE_SRCREV"))
> +    # Check which SPDX class is inherited
> +    inherits = (d.getVar("INHERIT") or "")

You really should use instead: bb.data.inherits_class("create-spdx-2.2", d)
This remark applies to various places.

> +    if "create-spdx-2.2" in inherits:
> +        bb.build.addtask("do_scout_extra_kernel_vulns", "do_build", "do_rootfs", d)
> +    elif "create-spdx" in inherits:
> +        bb.build.addtask('do_scout_extra_kernel_vulns', 'do_build', 'do_create_image_sbom_spdx', d)
> +}
> +
> +python do_clean:append() {
> +    import os, glob
> +    deploy_dir = d.expand('${DEPLOY_DIR_IMAGE}')
> +    for f in glob.glob(os.path.join(deploy_dir, '*scouted.json')):
> +        bb.note("Removing " + f)
> +        os.remove(f)
> +}
> +
> +python do_clone_kernel_cve() {
> +    import subprocess
> +    import shutil, os
> +    # Check if the system is using SPDX 3.0
> +    inherit_var = d.getVar("INHERIT")

Same here.

> +    preferred_provider = d.getVar("IMPROVE_KERNEL_PREFERRED_PROVIDER")
> +    if preferred_provider not in inherit_var:
> +        bb.warn(f"improve_kernel_cve: Requires the class {preferred_provider} enable in INHERIT variable.")
> +        return
> +    network_allowed = d.getVar("IMPROVE_KERNEL_CVE_NETWORK") == "1"
> +    workdir = d.getVar("IMPROVE_KERNEL_CVE_WORKDIR")
> +    unpack_dir = d.getVar("IMPROVE_KERNEL_CVE_UNPACK_DIR")
> +    # Remove existing unpacked directory if any
> +    if os.path.exists(workdir):
> +        shutil.rmtree(workdir)
> +    # Prepare fetcher
> +    src_uri_list = (d.getVar('SRC_URI') or "").split()
> +    cve_uris = []
> +    for uri in src_uri_list:
> +        if "name=improve-kernel-cve" in uri:
> +            cve_uris.append(uri)
> +    if not cve_uris:
> +        bb.note("No CVE exclusions SRC_URI found, skipping fetch")
> +        return
> +    fetcher = bb.fetch2.Fetch(cve_uris, d)
> +    # Clone only if network is allowed
> +    if network_allowed:
> +        fetcher.download()
> +    else:
> +        # Offline mode without network access
> +        bb.note("IMPROVE_KERNEL_CVE_NETWORK=0: Skipping online fetch. Checking local downloads in DL_DIR...")
> +        have_sources = False
> +        dl_dir = d.getVar("DL_DIR")
> +        srcrev = d.getVar("SRCREV_improve-kernel-cve")
> +        bb.note(f"Checking for sources for SRCREV: {srcrev}")
> +        # Check SRCREV is NOT set to AUTOREV
> +        if srcrev.strip() in ("${AUTOREV}", "AUTOINC", "INVALID"):
> +            bb.fatal("improve-kernel-cve: Offline mode but SRCREV is set to AUTOREV/AUTOINC/INVALID. Cannot proceed without network access or use a fixed SRCREV.")
> +            return
> +        # Loop through the fetcher's expanded URL data
> +        for ud in fetcher.expanded_urldata():
> +            ud.setup_localpath(d)
> +            # Check mirror tarballs first
> +            for mirror_fname in ud.mirrortarballs:
> +                mirror_path = os.path.join(dl_dir, mirror_fname)
> +                if os.path.exists(mirror_path):
> +                    bb.note(f"Found mirror tarball: {mirror_path}")
> +                    have_sources = True
> +                    break
> +            # If no mirror, check original download path
> +            if not have_sources and ud.localpath and os.path.exists(ud.localpath):
> +                bb.note(f"Found local download: {ud.localpath}")
> +                have_sources = True
> +            if not have_sources:
> +                bb.fatal("improve-kernel-cve: Offline mode but required source is missing.\n"f"SRC_URI = {ud.url}")
> +                return
> +    # Unpack into the standard work directory
> +    fetcher.unpack(unpack_dir)
> +    # Remove the folder ${PN} set by unpack
> +    subdirs = [d for d in os.listdir(unpack_dir) if os.path.isdir(os.path.join(unpack_dir, d))]
> +    if len(subdirs) == 1:
> +        srcdir = os.path.join(unpack_dir, subdirs[0])
> +        for f in os.listdir(srcdir):
> +            shutil.move(os.path.join(srcdir, f), unpack_dir)
> +        shutil.rmtree(srcdir)
> +}

I am not sure I understand this task. Since the 
git.kernel.org/pub/scm/linux/security/vulns.git is put in SRC_URI it really
should already be downloaded for you. Why are you managing the download
manually here?

> +do_clone_kernel_cve[network] = "${IMPROVE_KERNEL_CVE_NETWORK}"
> +do_clone_kernel_cve[nostamp] = "1"
> +do_clone_kernel_cve[doc] = "Clone the latest kernel vulnerabilities from https://git.kernel.org/pub/scm/linux/security/vulns.git"
> +addtask clone_kernel_cve after do_fetch before do_scout_extra_kernel_vulns
> +
> +do_scout_extra_kernel_vulns() {
> +    new_cve_report_file="${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.scouted.json"
> +    improve_kernel_cve_script="${COREBASE}/scripts/contrib/improve_kernel_cve_report.py"
> +
> +    # Check that IMPROVE_KERNEL_SPDX_FILE is set and the file exists
> +    if [ -z "${IMPROVE_KERNEL_SPDX_FILE}" ] || [ ! -f "${IMPROVE_KERNEL_SPDX_FILE}" ]; then
> +        bbwarn "improve_kernel_cve: IMPROVE_KERNEL_SPDX_FILE is empty or file not found: ${IMPROVE_KERNEL_SPDX_FILE}"
> +        return 0
> +    fi
> +    if [ ! -f "${CVE_CHECK_MANIFEST_JSON}" ]; then
> +        bbwarn "improve_kernel_cve: CVE_CHECK file not found: ${CVE_CHECK_MANIFEST_JSON}. Skipping extra kernel vulnerabilities scouting."
> +        return 0
> +    fi
> +    if [ ! -f "${improve_kernel_cve_script}" ]; then
> +        bbwarn "improve_kernel_cve: improve_kernel_cve_report.py not found in ${COREBASE}."
> +        return 0
> +    fi
> +    if [ ! -d "${IMPROVE_KERNEL_CVE_WORKDIR}" ]; then
> +        bbwarn "improve_kernel_cve: Vulnerabilities data not found in ${IMPROVE_KERNEL_CVE_WORKDIR}."
> +        return 0
> +    fi
> +
> +    #Run the improve_kernel_cve_report.py script
> +    bbplain "improve_kernel_cve: Using SPDX file for extra kernel vulnerabilities scouting: ${IMPROVE_KERNEL_SPDX_FILE}"
> +    python3 "${improve_kernel_cve_script}" \
> +        --spdx "${IMPROVE_KERNEL_SPDX_FILE}" \
> +        --old-cve-report "${CVE_CHECK_MANIFEST_JSON}" \
> +        --new-cve-report "${new_cve_report_file}" \
> +        --datadir "${IMPROVE_KERNEL_CVE_WORKDIR}"
> +    bbplain "Improve CVE report with extra kernel cves: ${new_cve_report_file}"
> +
> +    #Create a symlink as every other JSON file in tmp/deploy/images
> +    ln -sf ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.scouted.json ${DEPLOY_DIR_IMAGE}/${IMAGE_BASENAME}${IMAGE_MACHINE_SUFFIX}${IMAGE_NAME_SUFFIX}.scouted.json
> +}
> +do_scout_extra_kernel_vulns[nostamp] = "1"

Technically, this task only needs to be executed when the SPDX has changed or
when the vulns.git reference has changed.

> +do_scout_extra_kernel_vulns[doc] = "Scout extra kernel vulnerabilities and create a new enhanced version of the cve_check file in the deploy directory"
> \ No newline at end of file
> diff --git a/meta/classes/improve_kernel_cve_report-spdx-2.2.bbclass b/meta/classes/improve_kernel_cve_report-spdx-2.2.bbclass
> new file mode 100644
> index 0000000000..45b483134d
> --- /dev/null
> +++ b/meta/classes/improve_kernel_cve_report-spdx-2.2.bbclass
> @@ -0,0 +1,4 @@
> +IMPROVE_KERNEL_PREFERRED_PROVIDER = "create-spdx-2.2"
> +IMPROVE_KERNEL_SPDX_FILE = "${DEPLOY_DIR}/spdx/2.2/${@d.getVar('MACHINE').replace('-', '_')}/recipes/recipe-${PREFERRED_PROVIDER_virtual/kernel}.spdx.json"
> +
> +inherit improve_kernel_cve_report-base
> \ No newline at end of file
> diff --git a/meta/classes/improve_kernel_cve_report-spdx.bbclass b/meta/classes/improve_kernel_cve_report-spdx.bbclass
> new file mode 100644
> index 0000000000..3849f66aaf
> --- /dev/null
> +++ b/meta/classes/improve_kernel_cve_report-spdx.bbclass
> @@ -0,0 +1,4 @@
> +IMPROVE_KERNEL_PREFERRED_PROVIDER = "create-spdx"

You really want to specify here "create-spdx-3.0".
Also, maybe name the bbclass with a -3.0 suffix.


> +IMPROVE_KERNEL_SPDX_FILE = "${SPDXIMAGEDEPLOYDIR}/${IMAGE_LINK_NAME}.spdx.json"
> +
> +inherit improve_kernel_cve_report-base

Best regards,
-- 
Benjamin Robin, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com