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 6F5E232571E; Wed, 29 Oct 2025 12:25:07 +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=1761740707; cv=none; b=KYFprGrMS3ziLr1PFTFLan5v7pg8ARB5PUKVhVkXtQE6f/EfwMwpK2ugM+IysVXaP0lURUftPSDeefOekp9zymYh3qLijJNnce0U2NIwXXE/fTPSlJZv066m9vtrf/453idgbOcAM0A/0sjT450vw5zelQ2uU5FL3zSwWNCDBFs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761740707; c=relaxed/simple; bh=jlxGmvG3TRBGBU95oespXIKDq7FaoNyvL6StJ8L+zuI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=uDPOELeiaUD8UpIpHz6IBqbEf1XUvsKmeRk23G7USmPGsloUVrmNBwMTZB+7DsF091EVxFwJXC/mZs4dPOZ13fNQAehRUxvk0iyCPJVHK5hpFE+rPEz8hI44W+W6Y9zsP+GuIJl65MDTCXBb+i7xM6C8W16dRFbqygHL5lb/CUs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TC9qBPjf; 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="TC9qBPjf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E38E4C4CEFF; Wed, 29 Oct 2025 12:25:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761740707; bh=jlxGmvG3TRBGBU95oespXIKDq7FaoNyvL6StJ8L+zuI=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=TC9qBPjfKtifYJDMZ/N6sYRg7ELkUeMVr4eLWqPhD/M3R4uoEPYLEPoBOg52npPQ0 JdN5oqDtu5qn7hEoAfHN2S4Ejh5V+CgoNvDS6jNPH29gtedcvqSwNrHiEbRsIwPcDb QwZNTCiwn+3UEjWhyTHStKK5sy3JfIjTEF8zB632w231XBv2awcGt6D70YksqPXwGR RluH8byN9gf+qamBaGvO6M+vE0qEoLL7zWsRs8PuK4V7DwMHnMtZCByUcbcxKyFDTA g9xTQcIkBocKNgoFIHhCVlsSB8t/mneHjuQiORT8j36hSm7In7O+C0Yk6b14NG2EXI hF3SLKLyjPc8w== From: Christian Brauner Date: Wed, 29 Oct 2025 13:21:06 +0100 Subject: [PATCH v4 53/72] selftests/namespaces: sixth listns() permission test Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20251029-work-namespace-nstree-listns-v4-53-2e6f823ebdc0@kernel.org> References: <20251029-work-namespace-nstree-listns-v4-0-2e6f823ebdc0@kernel.org> In-Reply-To: <20251029-work-namespace-nstree-listns-v4-0-2e6f823ebdc0@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=2646; i=brauner@kernel.org; h=from:subject:message-id; bh=jlxGmvG3TRBGBU95oespXIKDq7FaoNyvL6StJ8L+zuI=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWQysfWz10z497741aVm25lC52dVWXhNvf1M+tg9pW19j txC71+6dpSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAEzkwVlGhraVl+Ps5trMDLd4 ZX7/2Jnuao+j1+fOSPqv1TNr9rZ+6+eMDPfmh0+ui5J/m231YiJLo+jdwmXCd5ZpK5/7mrtoe+P Tr6wA 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 | 87 ++++++++++++++++++++++ 1 file changed, 87 insertions(+) diff --git a/tools/testing/selftests/namespaces/listns_permissions_test.c b/tools/testing/selftests/namespaces/listns_permissions_test.c index b990b785dd7f..9aa06ff76333 100644 --- a/tools/testing/selftests/namespaces/listns_permissions_test.c +++ b/tools/testing/selftests/namespaces/listns_permissions_test.c @@ -561,4 +561,91 @@ 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)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + ASSERT_TRUE(found_ours); + TH_LOG("Process can see user namespace it has CAP_SYS_ADMIN inside of"); +} + TEST_HARNESS_MAIN -- 2.47.3