{"id":2231579,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2231579/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/patch/177758363712.1314717.16316935834409248821.stgit@frogsfrogsfrogs/","project":{"id":8,"url":"http://patchwork.ozlabs.org/api/1.1/projects/8/?format=json","name":"Linux ext4 filesystem development","link_name":"linux-ext4","list_id":"linux-ext4.vger.kernel.org","list_email":"linux-ext4@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<177758363712.1314717.16316935834409248821.stgit@frogsfrogsfrogs>","date":"2026-04-30T21:17:37","name":"[10/13] mount_service: allow installation as a setuid program","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"fc9b9e53eda75678a6057254b82dd7ff9874aee5","submitter":{"id":77032,"url":"http://patchwork.ozlabs.org/api/1.1/people/77032/?format=json","name":"Darrick J. Wong","email":"djwong@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-ext4/patch/177758363712.1314717.16316935834409248821.stgit@frogsfrogsfrogs/mbox/","series":[{"id":502386,"url":"http://patchwork.ozlabs.org/api/1.1/series/502386/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/list/?series=502386","date":"2026-04-30T21:15:17","name":"[01/13] Refactor mount code / move common functions to mount_util.c","version":1,"mbox":"http://patchwork.ozlabs.org/series/502386/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2231579/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2231579/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-ext4@vger.kernel.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","patchwork-incoming@ozlabs.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=LMXm0wUi;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=2404:9400:2221:ea00::3; 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arc=none smtp.client-ip=10.30.226.201"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1777583858;\n\tbh=UNCbDvUix/6fcD3ir7GQaG2O0AXlLax60sqntYviLZM=;\n\th=Date:Subject:From:To:Cc:In-Reply-To:References:From;\n\tb=LMXm0wUiMfMZNpeVuWyeT139GgaLa+Y9MDxCr0aLohFqdUFGIQkwikXMYk/qK4nGK\n\t jjNrMFGpOncNWJchh3wiObTATYYcNF+lPZGsm5lIthXF5WMhDsN1UBZNXOMoDWgs8A\n\t EAqFQUr13RgD5LC8Cjkvimy4J6Q6qLi/pG+shptnNYmrct2dZqa1xfaTWjtzhMt/xl\n\t LS+I1wFqf7vQtKwFFgiILy4tZHzGB5H/+nmLcw+aNJZ4KoKLNuhAI35WZQWGeWcS92\n\t RMMAbT1zccRhwowPhfBm8VacXoe6xmGy4tsOoT9KVTnQ4crZ3U9Ql8RdakRlgz5ngR\n\t cNlVXAQp4KAkg==","Date":"Thu, 30 Apr 2026 14:17:37 -0700","Subject":"[PATCH 10/13] mount_service: allow installation as a setuid program","From":"\"Darrick J. Wong\" ","To":"bernd@bsbernd.com, djwong@kernel.org","Cc":"linux-fsdevel@vger.kernel.org, fuse-devel@lists.linux.dev,\n linux-ext4@vger.kernel.org, miklos@szeredi.hu, neal@gompa.dev,\n joannelkoong@gmail.com","Message-ID":"<177758363712.1314717.16316935834409248821.stgit@frogsfrogsfrogs>","In-Reply-To":"<177758363484.1314717.11777978893472254088.stgit@frogsfrogsfrogs>","References":"<177758363484.1314717.11777978893472254088.stgit@frogsfrogsfrogs>","Precedence":"bulk","X-Mailing-List":"linux-ext4@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"7bit","X-Spam-Status":"No, score=-1.2 required=5.0 tests=ARC_SIGNED,ARC_VALID,\n\tDKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DMARC_PASS,\n\tMAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=disabled\n\tversion=4.0.1","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on gandalf.ozlabs.org"},"content":"From: Darrick J. Wong \n\nAllow installation of the mount service helper as a setuid program so\nthat regular users can access containerized filesystem drivers.\n\nSigned-off-by: \"Darrick J. Wong\" \n---\n README.md | 3 +++\n test/ci-build.sh | 14 ++++++++++++++\n util/install_helper.sh | 6 ++++++\n util/meson.build | 3 ++-\n 4 files changed, 25 insertions(+), 1 deletion(-)","diff":"diff --git a/README.md b/README.md\nindex 6cf23cd870109a..92b85522e7890a 100644\n--- a/README.md\n+++ b/README.md\n@@ -98,6 +98,9 @@ Security implications\n \n The *fusermount3* program is installed setuid root. This is done to\n allow normal users to mount their own filesystem implementations.\n+If built, the *fuservicemount3* program will also be installed setuid\n+root so that normal users can access containerized filesystem\n+implementations.\n \n To limit the harm that malicious users can do this way, *fusermount3*\n enforces the following limitations:\ndiff --git a/test/ci-build.sh b/test/ci-build.sh\nindex 8b019a0b5e52c1..f6e6c3d9de4e4e 100755\n--- a/test/ci-build.sh\n+++ b/test/ci-build.sh\n@@ -60,11 +60,18 @@ non_sanitized_build()\n \n # libfuse will first try the install path and then system defaults\n sudo chmod 4755 ${PREFIX_DIR}/bin/fusermount3\n+ test -x \"${PREFIX_DIR}/sbin/fuservicemount3\" && \\\n+ sudo chmod 4755 ${PREFIX_DIR}/sbin/fuservicemount3\n \n # also needed for some of the tests\n sudo chown root:root util/fusermount3\n sudo chmod 4755 util/fusermount3\n \n+ if [ -x util/fuservicemount3 ]; then\n+ sudo chown root:root util/fuservicemount3\n+ sudo chmod 4755 util/fuservicemount3\n+ fi\n+\n ${TEST_CMD}\n popd\n rm -fr build-${CC}\n@@ -101,11 +108,18 @@ sanitized_build()\n ninja\n sudo env PATH=$PATH ninja install\n sudo chmod 4755 ${PREFIX_DIR}/bin/fusermount3\n+ test -x \"${PREFIX_DIR}/sbin/fuservicemount3\" && \\\n+ sudo chmod 4755 ${PREFIX_DIR}/sbin/fuservicemount3\n \n # also needed for some of the tests\n sudo chown root:root util/fusermount3\n sudo chmod 4755 util/fusermount3\n \n+ if [ -x util/fuservicemount3 ]; then\n+ sudo chown root:root util/fuservicemount3\n+ sudo chmod 4755 util/fuservicemount3\n+ fi\n+\n # Test as root and regular user\n sudo env PATH=$PATH ${TEST_CMD}\n # Cleanup temporary files (since they are now owned by root)\ndiff --git a/util/install_helper.sh b/util/install_helper.sh\nindex 76f2b47fe6c8f9..4c6f9dc3dc70aa 100755\n--- a/util/install_helper.sh\n+++ b/util/install_helper.sh\n@@ -11,6 +11,7 @@ bindir=\"$2\"\n udevrulesdir=\"$3\"\n useroot=\"$4\"\n initscriptdir=\"$5\"\n+sbindir=\"$6\"\n \n # Both sysconfdir and bindir are absolute paths (since they are joined\n # with --prefix in meson.build), but need to be interpreted relative\n@@ -31,6 +32,11 @@ if $useroot; then\n chown root:root \"${DESTDIR}${bindir}/fusermount3\"\n chmod u+s \"${DESTDIR}${bindir}/fusermount3\"\n \n+ if [ -e \"${DESTDIR}${sbindir}/fuservicemount3\" ]; then\n+ chown root:root \"${DESTDIR}${sbindir}/fuservicemount3\"\n+ chmod u+s \"${DESTDIR}${sbindir}/fuservicemount3\"\n+ fi\n+\n if test ! -e \"${DESTDIR}/dev/fuse\"; then\n mkdir -p \"${DESTDIR}/dev\"\n mknod \"${DESTDIR}/dev/fuse\" -m 0666 c 10 229\ndiff --git a/util/meson.build b/util/meson.build\nindex 85b54d5d322dcb..e15dd9bbb0c486 100644\n--- a/util/meson.build\n+++ b/util/meson.build\n@@ -46,4 +46,5 @@ meson.add_install_script('install_helper.sh',\n join_paths(get_option('prefix'), get_option('bindir')),\n udevrulesdir,\n '@0@'.format(get_option('useroot')),\n- get_option('initscriptdir'))\n+ get_option('initscriptdir'),\n+ join_paths(get_option('prefix'), get_option('sbindir')))\n","prefixes":["10/13"]}