From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Lutomirski Subject: [WIP 2/4] bpf: Don't require mknod() permission to pin an object Date: Mon, 5 Aug 2019 14:29:03 -0700 Message-ID: <3bb110117c983f781f545e69ce35d4fcdd0c543b.1565040372.git.luto@kernel.org> References: Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Sender: netdev-owner@vger.kernel.org To: LKML , Alexei Starovoitov Cc: Song Liu , Kees Cook , Networking , bpf , Daniel Borkmann , Alexei Starovoitov , Kernel Team , Lorenz Bauer , Jann Horn , Greg KH , Linux API , LSM List , Andy Lutomirski List-Id: linux-api@vger.kernel.org security_path_mknod() seems excessive for pinning an object -- pinning an object is effectively just creating a file. It's also redundant, as vfs_mkobj() calls security_inode_create() by itself. This isn't strictly required -- mknod(path, S_IFREG, unused) works to create regular files, but bpf is currently the only user in the kernel outside of mknod() itself that uses it to create regular (i.e. S_IFREG) files. Signed-off-by: Andy Lutomirski --- kernel/bpf/inode.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index cb07736b33ae..14304609003a 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -394,10 +394,6 @@ static int bpf_obj_do_pin(const struct filename *pathname, void *raw, mode = S_IFREG | ((S_IRUSR | S_IWUSR) & ~current_umask()); - ret = security_path_mknod(&path, dentry, mode, 0); - if (ret) - goto out; - dir = d_inode(path.dentry); if (dir->i_op != &bpf_dir_iops) { ret = -EPERM; -- 2.21.0