From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 AC6A7340282; Tue, 21 Oct 2025 11:48:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761047287; cv=none; b=kiMEmARdPjo63NfmdTNU8WOrf/DAtlPVggRwgslDvc4E3LiZJmBwseL/IBc6LY1Vxq0bZiet1DHNBX4srixGxPAOGs5holTpm9p1+C/GBD9S5Ok/mzA3AWrXA8Kt1CJmevXkqL6+/5lWcYRrd4OeoulO7pVKceFKcwyNIrEbXWE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761047287; c=relaxed/simple; bh=zyvSyEvHN08sO6ilDq1bp8H9I2nWZ5I4e4dJ8kwOeEM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=GyCQN9ul07K1TR22OY4rCe/lw7dPggN6lNk+ctrIRUbx+83SiBe3Rz3Zy9Qe440wbfAnodzax+c0vv+gEi1cOldya92Jp6a05vK/hJE1FGo8sZos7gu4DeEXrrwoi2w8u9L4cJVWPleqMBQNZCdgXcg9m5+5A+uZhRMItXo47m4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k56CjcQr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k56CjcQr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4518C4CEFD; Tue, 21 Oct 2025 11:48:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761047287; bh=zyvSyEvHN08sO6ilDq1bp8H9I2nWZ5I4e4dJ8kwOeEM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=k56CjcQrfgL+lHhiTYqs67nqOzI9yjnL60HczgPgk/cbHjhtjU90xZrLGBKG9orB2 s03OMJPSaflfkuWJEkQ/RwHvY7m/pDFhb5ZcDCrtFYaabfCMkSYdyx7JMxspnH6+av FMAsBSr51lbsaQwqv28YpvfBHp7oy6p6EM1BjyTHY/Mz96YnJp4/WCnj4pbNIc31lr +bN9In4VojYUg392Ar4bZ69zyIdY8T1fBw99jXw8LFKoIrow40eS3XS4PY23ZZ3/c8 vB2VDw7QevxzaDEM0ZzNjuDgxXXV3N+S1YQxKV7EXXbTxGO6iLZs4Dx9OGmiiMknNg ogERhEF6SREaA== From: Christian Brauner Date: Tue, 21 Oct 2025 13:43:55 +0200 Subject: [PATCH RFC DRAFT 49/50] selftests/namespaces: sixth listns() permission test Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251021-work-namespace-nstree-listns-v1-49-ad44261a8a5b@kernel.org> References: <20251021-work-namespace-nstree-listns-v1-0-ad44261a8a5b@kernel.org> In-Reply-To: <20251021-work-namespace-nstree-listns-v1-0-ad44261a8a5b@kernel.org> To: linux-fsdevel@vger.kernel.org, Josef Bacik , Jeff Layton Cc: Jann Horn , Mike Yuan , =?utf-8?q?Zbigniew_J=C4=99drzejewski-Szmek?= , Lennart Poettering , Daan De Meyer , Aleksa Sarai , Amir Goldstein , Tejun Heo , Johannes Weiner , Thomas Gleixner , Alexander Viro , Jan Kara , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, Eric Dumazet , Jakub Kicinski , netdev@vger.kernel.org, Arnd Bergmann , Christian Brauner X-Mailer: b4 0.15-dev-96507 X-Developer-Signature: v=1; a=openpgp-sha256; l=2704; i=brauner@kernel.org; h=from:subject:message-id; bh=zyvSyEvHN08sO6ilDq1bp8H9I2nWZ5I4e4dJ8kwOeEM=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWR8L3yvX7suviu+Wc3jXf/3P2F+Cp7rN8Y9ME1RqLy7o 4qt8/bbjlIWBjEuBlkxRRaHdpNwueU8FZuNMjVg5rAygQxh4OIUgIlIxTP8zzmeuENn9nLGR21K U1fOdDhsr/Y08uj8cwJO3VOmztj0+wDD/+Ar5u4VnSs+Czm3uDgkHLT2ebtPeJnZzuutoVfZYi3 m8gEA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Test that we can see user namespaces we have CAP_SYS_ADMIN inside of. This is different from seeing namespaces owned by a user namespace. Signed-off-by: Christian Brauner --- .../selftests/namespaces/listns_permissions_test.c | 90 ++++++++++++++++++++++ 1 file changed, 90 insertions(+) diff --git a/tools/testing/selftests/namespaces/listns_permissions_test.c b/tools/testing/selftests/namespaces/listns_permissions_test.c index 07c0c2be0aa5..709250ce1542 100644 --- a/tools/testing/selftests/namespaces/listns_permissions_test.c +++ b/tools/testing/selftests/namespaces/listns_permissions_test.c @@ -573,4 +573,94 @@ TEST(listns_parent_userns_cap_sys_admin) count); } +/* + * Test that we can see user namespaces we have CAP_SYS_ADMIN inside of. + * This is different from seeing namespaces owned by a user namespace. + */ +TEST(listns_cap_sys_admin_inside_userns) +{ + int pipefd[2]; + pid_t pid; + int status; + bool found_ours; + + ASSERT_EQ(pipe(pipefd), 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + int fd; + __u64 our_userns_id; + struct ns_id_req req; + __u64 ns_ids[100]; + ssize_t ret; + bool found_ours; + + close(pipefd[0]); + + /* Create user namespace - we have CAP_SYS_ADMIN inside it */ + if (setup_userns() < 0) { + close(pipefd[1]); + exit(1); + } + + /* Get our user namespace ID */ + fd = open("/proc/self/ns/user", O_RDONLY); + if (fd < 0) { + close(pipefd[1]); + exit(1); + } + + if (ioctl(fd, NS_GET_ID, &our_userns_id) < 0) { + close(fd); + close(pipefd[1]); + exit(1); + } + close(fd); + + /* List all user namespaces globally */ + req.size = sizeof(req); + req.spare = 0; + req.ns_id = 0; + req.ns_type = CLONE_NEWUSER; + req.spare2 = 0; + req.user_ns_id = 0; + + ret = sys_listns(&req, ns_ids, ARRAY_SIZE(ns_ids), 0); + + /* We should be able to see our own user namespace */ + found_ours = false; + if (ret > 0) { + for (ssize_t i = 0; i < ret; i++) { + if (ns_ids[i] == our_userns_id) { + found_ours = true; + break; + } + } + } + + write(pipefd[1], &found_ours, sizeof(found_ours)); + close(pipefd[1]); + exit(0); + } + + /* Parent */ + close(pipefd[1]); + + found_ours = false; + read(pipefd[0], &found_ours, sizeof(found_ours)); + close(pipefd[0]); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + + if (WEXITSTATUS(status) != 0) { + SKIP(return, "Child failed to setup namespace"); + } + + ASSERT_TRUE(found_ours); + TH_LOG("Process can see user namespace it has CAP_SYS_ADMIN inside of"); +} + TEST_HARNESS_MAIN -- 2.47.3