From patchwork Tue Mar 24 20:44:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Gladkov X-Patchwork-Id: 11456513 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EE5FF14B4 for ; Tue, 24 Mar 2020 20:46:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1A16208D5 for ; Tue, 24 Mar 2020 20:46:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728187AbgCXUqP (ORCPT ); Tue, 24 Mar 2020 16:46:15 -0400 Received: from monster.unsafe.ru ([5.9.28.80]:38552 "EHLO mail.unsafe.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727061AbgCXUqO (ORCPT ); Tue, 24 Mar 2020 16:46:14 -0400 Received: from comp-core-i7-2640m-0182e6.redhat.com (ip-89-102-33-211.net.upcbroadband.cz [89.102.33.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.unsafe.ru (Postfix) with ESMTPSA id 8D604C61B28; Tue, 24 Mar 2020 20:46:11 +0000 (UTC) From: Alexey Gladkov To: LKML , Kernel Hardening , Linux API , Linux FS Devel , Linux Security Module Cc: Akinobu Mita , Alexander Viro , Alexey Dobriyan , Alexey Gladkov , Andrew Morton , Andy Lutomirski , Daniel Micay , Djalal Harouni , "Dmitry V . Levin" , "Eric W . Biederman" , Greg Kroah-Hartman , Ingo Molnar , "J . Bruce Fields" , Jeff Layton , Jonathan Corbet , Kees Cook , Linus Torvalds , Oleg Nesterov Subject: [PATCH RESEND v9 3/8] proc: move hide_pid, pid_gid from pid_namespace to proc_fs_info Date: Tue, 24 Mar 2020 21:44:44 +0100 Message-Id: <20200324204449.7263-4-gladkov.alexey@gmail.com> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200324204449.7263-1-gladkov.alexey@gmail.com> References: <20200324204449.7263-1-gladkov.alexey@gmail.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Move hide_pid and pid_gid parameters inside procfs fs_info struct instead of making them per pid namespace. Since we have a multiple procfs instances per pid namespace we need to make sure that all proc-specific parameters are also per-superblock. Signed-off-by: Alexey Gladkov Reviewed-by: Alexey Dobriyan --- fs/proc/base.c | 18 +++++++++--------- fs/proc/inode.c | 9 ++++----- fs/proc/root.c | 4 ++-- include/linux/pid_namespace.h | 8 -------- include/linux/proc_fs.h | 9 +++++++++ 5 files changed, 24 insertions(+), 24 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 9d2e425338c8..984b97bb634b 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -697,13 +697,13 @@ int proc_setattr(struct dentry *dentry, struct iattr *attr) * May current process learn task's sched/cmdline info (for hide_pid_min=1) * or euid/egid (for hide_pid_min=2)? */ -static bool has_pid_permissions(struct pid_namespace *pid, +static bool has_pid_permissions(struct proc_fs_info *fs_info, struct task_struct *task, int hide_pid_min) { - if (pid->hide_pid < hide_pid_min) + if (fs_info->hide_pid < hide_pid_min) return true; - if (in_group_p(pid->pid_gid)) + if (in_group_p(fs_info->pid_gid)) return true; return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); } @@ -711,18 +711,18 @@ static bool has_pid_permissions(struct pid_namespace *pid, static int proc_pid_permission(struct inode *inode, int mask) { - struct pid_namespace *pid = proc_pid_ns(inode); + struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb); struct task_struct *task; bool has_perms; task = get_proc_task(inode); if (!task) return -ESRCH; - has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); + has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS); put_task_struct(task); if (!has_perms) { - if (pid->hide_pid == HIDEPID_INVISIBLE) { + if (fs_info->hide_pid == HIDEPID_INVISIBLE) { /* * Let's make getdents(), stat(), and open() * consistent with each other. If a process @@ -1897,7 +1897,7 @@ int pid_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *inode = d_inode(path->dentry); - struct pid_namespace *pid = proc_pid_ns(inode); + struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb); struct task_struct *task; generic_fillattr(inode, stat); @@ -1907,7 +1907,7 @@ int pid_getattr(const struct path *path, struct kstat *stat, rcu_read_lock(); task = pid_task(proc_pid(inode), PIDTYPE_PID); if (task) { - if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { + if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) { rcu_read_unlock(); /* * This doesn't prevent learning whether PID exists, @@ -3402,7 +3402,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) unsigned int len; cond_resched(); - if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) + if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE)) continue; len = snprintf(name, sizeof(name), "%u", iter.tgid); diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 6e4c6728338b..91fe4896fa85 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -168,12 +168,11 @@ void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock static int proc_show_options(struct seq_file *seq, struct dentry *root) { struct proc_fs_info *fs_info = proc_sb_info(root->d_sb); - struct pid_namespace *pid = fs_info->pid_ns; - 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 != HIDEPID_OFF) - seq_printf(seq, ",hidepid=%u", pid->hide_pid); + if (!gid_eq(fs_info->pid_gid, GLOBAL_ROOT_GID)) + seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, fs_info->pid_gid)); + if (fs_info->hide_pid != HIDEPID_OFF) + seq_printf(seq, ",hidepid=%u", fs_info->hide_pid); return 0; } diff --git a/fs/proc/root.c b/fs/proc/root.c index b28adbb0b937..616e8976185c 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -85,9 +85,9 @@ static void proc_apply_options(struct super_block *s, struct proc_fs_context *ctx = fc->fs_private; if (ctx->mask & (1 << Opt_gid)) - pid_ns->pid_gid = make_kgid(user_ns, ctx->gid); + ctx->fs_info->pid_gid = make_kgid(user_ns, ctx->gid); if (ctx->mask & (1 << Opt_hidepid)) - pid_ns->hide_pid = ctx->hidepid; + ctx->fs_info->hide_pid = ctx->hidepid; } static int proc_fill_super(struct super_block *s, struct fs_context *fc) diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 4956e362e55e..028d7ba242c6 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -17,12 +17,6 @@ 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 idr idr; @@ -41,8 +35,6 @@ struct pid_namespace { #endif struct user_namespace *user_ns; struct ucounts *ucounts; - kgid_t pid_gid; - int hide_pid; int reboot; /* group exit code if this pidns was rebooted */ struct ns_common ns; } __randomize_layout; diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 5920a4ecd71b..7d852dbca253 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -27,10 +27,19 @@ struct proc_ops { unsigned long (*proc_get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); }; +/* definitions for hide_pid field */ +enum { + HIDEPID_OFF = 0, + HIDEPID_NO_ACCESS = 1, + HIDEPID_INVISIBLE = 2, +}; + struct proc_fs_info { struct pid_namespace *pid_ns; struct dentry *proc_self; /* For /proc/self */ struct dentry *proc_thread_self; /* For /proc/thread-self */ + kgid_t pid_gid; + int hide_pid; }; static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)