From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751668AbdAPNX6 (ORCPT ); Mon, 16 Jan 2017 08:23:58 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:33433 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751584AbdAPNXw (ORCPT ); Mon, 16 Jan 2017 08:23:52 -0500 From: Djalal Harouni X-Google-Original-From: Djalal Harouni To: linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Cc: Andrew Morton , Kees Cook , Lafcadio Wluiki , Djalal Harouni Subject: [PATCH v4 1/2] procfs: use an enum for possible hidepid values Date: Mon, 16 Jan 2017 14:23:03 +0100 Message-Id: <1484572984-13388-2-git-send-email-djalal@gmail.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1484572984-13388-1-git-send-email-djalal@gmail.com> References: <1484572984-13388-1-git-send-email-djalal@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lafcadio Wluiki Previously, the hidepid parameter was checked by comparing literal integers 0, 1, 2. Let's add a proper enum for this, to make the checking more expressive: 0 → HIDEPID_OFF 1 → HIDEPID_NO_ACCESS 2 → HIDEPID_INVISIBLE This changes the internal labelling only, the userspace-facing interface remains unmodified, and still works with literal integers 0, 1, 2. No functional changes. Acked-by: Kees Cook Acked-by: Djalal Harouni Signed-off-by: Lafcadio Wluiki --- fs/proc/base.c | 8 ++++---- fs/proc/inode.c | 2 +- fs/proc/root.c | 3 ++- include/linux/pid_namespace.h | 6 ++++++ 4 files changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 8e7e61b..cd8dd15 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -729,11 +729,11 @@ static int proc_pid_permission(struct inode *inode, int mask) task = get_proc_task(inode); if (!task) return -ESRCH; - has_perms = has_pid_permissions(pid, task, 1); + has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); put_task_struct(task); if (!has_perms) { - if (pid->hide_pid == 2) { + if (pid->hide_pid == HIDEPID_INVISIBLE) { /* * Let's make getdents(), stat(), and open() * consistent with each other. If a process @@ -1725,7 +1725,7 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) stat->gid = GLOBAL_ROOT_GID; task = pid_task(proc_pid(inode), PIDTYPE_PID); if (task) { - if (!has_pid_permissions(pid, task, 2)) { + if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { rcu_read_unlock(); /* * This doesn't prevent learning whether PID exists, @@ -3179,7 +3179,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) iter.tgid += 1, iter = next_tgid(ns, iter)) { char name[PROC_NUMBUF]; int len; - if (!has_pid_permissions(ns, iter.task, 2)) + if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) continue; len = snprintf(name, sizeof(name), "%d", iter.tgid); diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 842a5ff..5d9bafb 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -106,7 +106,7 @@ static int proc_show_options(struct seq_file *seq, struct dentry *root) if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID)) seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid)); - if (pid->hide_pid != 0) + if (pid->hide_pid != HIDEPID_OFF) seq_printf(seq, ",hidepid=%u", pid->hide_pid); return 0; diff --git a/fs/proc/root.c b/fs/proc/root.c index 1988440..b90da88 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -58,7 +58,8 @@ int proc_parse_options(char *options, struct pid_namespace *pid) case Opt_hidepid: if (match_int(&args[0], &option)) return 0; - if (option < 0 || option > 2) { + if (option < HIDEPID_OFF || + option > HIDEPID_INVISIBLE) { pr_err("proc: hidepid value must be between 0 and 2.\n"); return 0; } diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 34cce96..c2a989d 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -21,6 +21,12 @@ struct pidmap { struct fs_pin; +enum { /* definitions for pid_namespace's hide_pid field */ + HIDEPID_OFF = 0, + HIDEPID_NO_ACCESS = 1, + HIDEPID_INVISIBLE = 2, +}; + struct pid_namespace { struct kref kref; struct pidmap pidmap[PIDMAP_ENTRIES]; -- 2.5.5