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 09F431C2324; Wed, 18 Jun 2025 23:37:48 +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=1750289869; cv=none; b=hPjApl2WZlX0zvBhEmqP2KCek2pBxbvSpsPE0nsRtmjiWL5ZCaJ1mVUb7Te6M8zPk9fqZ5h0gA0+n/VrIxUPQn/STXb7lSrMF4iCFlpYxIKgpXvHKKhOw8D72POfN32V84bA7VfFnrGFnYby0IwsTWMDXmlXJDgKPpzxzhLDpwU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750289869; c=relaxed/simple; bh=57U4HUj1TaKN/otMUBUDWLAiMAuN6kSRzu/C1u8g3Tk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=qVlrqMOnpH1NWbjNl4i0/avZHbqo45JkqNV07fnYcD+Jp947yXz5Qb3abiXP5+oUi86wYsRIND+JSYXac6LFNi6lggFTELxvZlW9Dt5WlzgJnngmjz3Rju1hwk6TAsiLHuz5SV4kPsfxw9Ca0AzgmTaUXqe4kZ0aVIwi5ybTeCc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j4F15rpw; 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="j4F15rpw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A125CC4CEE7; Wed, 18 Jun 2025 23:37:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750289868; bh=57U4HUj1TaKN/otMUBUDWLAiMAuN6kSRzu/C1u8g3Tk=; h=From:To:Cc:Subject:Date:From; b=j4F15rpwS3hjum2uic6o/rp9fqV3p2hbKVhFqSnOU11x12hvHb7WN34wsfhf0CV5w DSe4+fDMRbzSPfnGfwwOYWPI0SAew64BirgVZAxGsAL4uQ3ywROwix/QhgTftn2DiE ALdvPI5r6f8/peNq7ggbGGWBkxX6SHmLWyb5RVDiOZamb+XgvFju84QzE4SRj/DPPB l93bxMcdsU6g4Zx5RYokkjFubvVjAb3tL60CCamjX1vKEQ6JKBBE9GKQJt8RztUUyt 3dNGGawVud3Feuuvw82dESceNPU7X5otfG70+Y77Sx29bXy7HYYGcTlw0Ej5CzPGmj vwAY18NEC9SzQ== From: Song Liu To: bpf@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Cc: kernel-team@meta.com, andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, kpsingh@kernel.org, mattbobrowski@google.com, amir73il@gmail.com, gregkh@linuxfoundation.org, tj@kernel.org, daan.j.demeyer@gmail.com, Song Liu Subject: [PATCH bpf-next 0/4] Introduce bpf_kernfs_read_xattr Date: Wed, 18 Jun 2025 16:37:35 -0700 Message-ID: <20250618233739.189106-1-song@kernel.org> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Introduce a new kfunc bpf_kernfs_read_xattr, which can read xattr from kernfs nodes (cgroupfs, for example). The primary users are LSMs, for example, from systemd. sched_ext could also use xattrs on cgroupfs nodes. However, this is not allowed yet, because bpf_kernfs_read_xattr is only allowed from LSM hooks. The plan is to address sched_ext later (or in a later revision of this set). Song Liu (4): kernfs: Add __kernfs_xattr_get for RCU protected access bpf: Introduce bpf_kernfs_read_xattr to read xattr of kernfs nodes bpf: Mark cgroup_subsys_state->cgroup RCU safe selftests/bpf: Add tests for bpf_kernfs_read_xattr fs/bpf_fs_kfuncs.c | 33 ++++ fs/kernfs/inode.c | 14 ++ include/linux/kernfs.h | 2 + kernel/bpf/verifier.c | 5 + .../selftests/bpf/prog_tests/kernfs_xattr.c | 145 ++++++++++++++++++ .../selftests/bpf/progs/kernfs_read_xattr.c | 117 ++++++++++++++ .../selftests/bpf/progs/read_cgroupfs_xattr.c | 60 ++++++++ 7 files changed, 376 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/kernfs_xattr.c create mode 100644 tools/testing/selftests/bpf/progs/kernfs_read_xattr.c create mode 100644 tools/testing/selftests/bpf/progs/read_cgroupfs_xattr.c -- 2.47.1