From: Alexey Gladkov <gladkov.alexey@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
Linux API <linux-api@vger.kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
Linux Security Module <linux-security-module@vger.kernel.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Alexey Dobriyan <adobriyan@gmail.com>,
Alexey Gladkov <gladkov.alexey@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Daniel Micay <danielmicay@gmail.com>,
Djalal Harouni <tixxdz@gmail.com>,
"Dmitry V . Levin" <ldv@altlinux.org>,
"Eric W . Biederman" <ebiederm@xmission.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ingo Molnar <mingo@kernel.org>,
"J . Bruce Fields" <bfields@fieldses.org>,
Jeff Layton <jlayton@poochiereds.net>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>,
Solar Designer <solar@openwall.com>
Subject: [PATCH v8 04/11] proc: move hide_pid, pid_gid from pid_namespace to proc_fs_info
Date: Mon, 10 Feb 2020 16:05:12 +0100 [thread overview]
Message-ID: <20200210150519.538333-5-gladkov.alexey@gmail.com> (raw)
In-Reply-To: <20200210150519.538333-1-gladkov.alexey@gmail.com>
This is a preparation patch that moves hide_pid and pid_gid parameters
to be stored inside procfs fs_info struct instead of making them per pid
namespace. Since we want to support multiple procfs instances we need to
make sure that all proc-specific parameters are also per-superblock.
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
---
fs/proc/base.c | 18 +++++++++---------
fs/proc/inode.c | 9 ++++-----
fs/proc/root.c | 10 ++++++++--
include/linux/pid_namespace.h | 8 --------
include/linux/proc_fs.h | 9 +++++++++
5 files changed, 30 insertions(+), 24 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1eb366ad8b06..caca1929fee1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -695,13 +695,13 @@ 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);
}
@@ -709,18 +709,18 @@ 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
@@ -1784,7 +1784,7 @@ 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);
@@ -1794,7 +1794,7 @@ 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,
@@ -3344,7 +3344,7 @@ 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 b631608dfbcc..b90c233e5968 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -105,12 +105,11 @@ void __init proc_init_kmemcache(void)
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 637e26cc795e..1ca47d446aa4 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -89,10 +89,16 @@ static void proc_apply_options(struct super_block *s,
{
struct proc_fs_context *ctx = fc->fs_private;
+ if (pid_ns->proc_mnt) {
+ struct proc_fs_info *fs_info = proc_sb_info(pid_ns->proc_mnt->mnt_sb);
+ ctx->fs_info->pid_gid = fs_info->pid_gid;
+ ctx->fs_info->hide_pid = fs_info->hide_pid;
+ }
+
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 f91a8bf6e09e..66f47f1afe0d 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -15,12 +15,6 @@
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;
@@ -39,8 +33,6 @@ struct pid_namespace {
struct user_namespace *user_ns;
struct ucounts *ucounts;
struct work_struct proc_work;
- 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 59162988998e..5f0b1b7e4271 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -12,10 +12,19 @@ struct proc_dir_entry;
struct seq_file;
struct seq_operations;
+/* 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)
--
2.24.1
next prev parent reply other threads:[~2020-02-10 15:06 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-10 15:05 [PATCH v8 00/11] proc: modernize proc to support multiple private instances Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 01/11] proc: Rename struct proc_fs_info to proc_fs_opts Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 02/11] proc: add proc_fs_info struct to store proc information Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 03/11] proc: move /proc/{self|thread-self} dentries to proc_fs_info Alexey Gladkov
2020-02-10 18:23 ` Andy Lutomirski
2020-02-12 15:00 ` Alexey Gladkov
2020-02-10 15:05 ` Alexey Gladkov [this message]
2020-02-10 15:05 ` [PATCH v8 05/11] proc: add helpers to set and get proc hidepid and gid mount options Alexey Gladkov
2020-02-10 18:30 ` Andy Lutomirski
2020-02-12 14:57 ` Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 06/11] proc: support mounting procfs instances inside same pid namespace Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 07/11] proc: flush task dcache entries from all procfs instances Alexey Gladkov
2020-02-10 17:46 ` Linus Torvalds
2020-02-10 19:23 ` Al Viro
2020-02-11 1:36 ` Eric W. Biederman
2020-02-11 4:01 ` Eric W. Biederman
2020-02-12 14:49 ` Alexey Gladkov
2020-02-12 14:59 ` Eric W. Biederman
2020-02-12 17:08 ` Alexey Gladkov
2020-02-12 18:45 ` Linus Torvalds
2020-02-12 19:16 ` Eric W. Biederman
2020-02-12 19:49 ` Linus Torvalds
2020-02-12 20:03 ` Al Viro
2020-02-12 20:35 ` Linus Torvalds
2020-02-12 20:38 ` Al Viro
2020-02-12 20:41 ` Al Viro
2020-02-12 21:02 ` Linus Torvalds
2020-02-12 21:46 ` Eric W. Biederman
2020-02-13 0:48 ` Linus Torvalds
2020-02-13 4:37 ` Eric W. Biederman
2020-02-13 5:55 ` Al Viro
2020-02-13 21:30 ` Linus Torvalds
2020-02-13 22:23 ` Al Viro
2020-02-13 22:47 ` Linus Torvalds
2020-02-14 14:15 ` Eric W. Biederman
2020-02-14 3:48 ` Eric W. Biederman
2020-02-20 20:46 ` [PATCH 0/7] proc: Dentry flushing without proc_mnt Eric W. Biederman
2020-02-20 20:47 ` [PATCH 1/7] proc: Rename in proc_inode rename sysctl_inodes sibling_inodes Eric W. Biederman
2020-02-20 20:48 ` [PATCH 2/7] proc: Generalize proc_sys_prune_dcache into proc_prune_siblings_dcache Eric W. Biederman
2020-02-20 20:49 ` [PATCH 3/7] proc: Mov rcu_read_(lock|unlock) in proc_prune_siblings_dcache Eric W. Biederman
2020-02-20 22:33 ` Linus Torvalds
2020-02-20 20:49 ` [PATCH 4/7] proc: Use d_invalidate " Eric W. Biederman
2020-02-20 22:43 ` Linus Torvalds
2020-02-20 22:54 ` Al Viro
2020-02-20 23:00 ` Linus Torvalds
2020-02-20 23:03 ` Al Viro
2020-02-20 23:39 ` Eric W. Biederman
2020-02-20 20:51 ` [PATCH 5/7] proc: Clear the pieces of proc_inode that proc_evict_inode cares about Eric W. Biederman
2020-02-20 20:52 ` [PATCH 6/7] proc: Use a list of inodes to flush from proc Eric W. Biederman
2020-02-20 20:52 ` [PATCH 7/7] proc: Ensure we see the exit of each process tid exactly once Eric W. Biederman
2020-02-21 16:50 ` Oleg Nesterov
2020-02-22 15:46 ` Eric W. Biederman
2020-02-20 23:02 ` [PATCH 0/7] proc: Dentry flushing without proc_mnt Linus Torvalds
2020-02-20 23:07 ` Al Viro
2020-02-20 23:37 ` Eric W. Biederman
2020-02-24 16:25 ` [PATCH v2 0/6] " Eric W. Biederman
2020-02-24 16:26 ` [PATCH v2 1/6] proc: Rename in proc_inode rename sysctl_inodes sibling_inodes Eric W. Biederman
2020-02-24 16:27 ` [PATCH v2 2/6] proc: Generalize proc_sys_prune_dcache into proc_prune_siblings_dcache Eric W. Biederman
2020-02-24 16:27 ` [PATCH v2 3/6] proc: In proc_prune_siblings_dcache cache an aquired super block Eric W. Biederman
2020-02-24 16:28 ` [PATCH v2 4/6] proc: Use d_invalidate in proc_prune_siblings_dcache Eric W. Biederman
2020-02-24 16:28 ` [PATCH v2 5/6] proc: Clear the pieces of proc_inode that proc_evict_inode cares about Eric W. Biederman
2020-02-24 16:29 ` [PATCH v2 6/6] proc: Use a list of inodes to flush from proc Eric W. Biederman
2020-02-28 20:17 ` [PATCH 0/3] proc: Actually honor the mount options Eric W. Biederman
2020-02-28 20:18 ` [PATCH 1/3] uml: Don't consult current to find the proc_mnt in mconsole_proc Eric W. Biederman
2020-02-28 20:18 ` [PATCH 2/3] uml: Create a private mount of proc for mconsole Eric W. Biederman
2020-02-28 20:30 ` Christian Brauner
2020-02-28 21:28 ` Eric W. Biederman
2020-02-28 21:59 ` Christian Brauner
2020-02-28 20:19 ` [PATCH 3/3] proc: Remove the now unnecessary internal mount of proc Eric W. Biederman
2020-02-28 20:39 ` Christian Brauner
2020-02-28 21:40 ` Eric W. Biederman
2020-02-29 3:25 ` kbuild test robot
2020-02-29 4:49 ` Eric W. Biederman
2020-03-02 23:01 ` [kbuild-all] " Philip Li
2020-03-12 2:03 ` Li Zhijian
2020-02-29 4:23 ` kbuild test robot
2020-02-28 22:34 ` [PATCH 4/3] pid: Improve the comment about waiting in zap_pid_ns_processes Eric W. Biederman
2020-02-29 2:59 ` Christian Brauner
2020-02-14 3:49 ` [PATCH v8 07/11] proc: flush task dcache entries from all procfs instances Eric W. Biederman
2020-02-12 19:47 ` Al Viro
2020-02-11 22:45 ` Al Viro
2020-02-12 14:26 ` Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 08/11] proc: instantiate only pids that we can ptrace on 'hidepid=4' mount option Alexey Gladkov
2020-02-10 16:29 ` Jordan Glover
2020-02-12 14:34 ` Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 09/11] proc: add option to mount only a pids subset Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 10/11] docs: proc: add documentation for "hidepid=4" and "subset=pidfs" options and new mount behavior Alexey Gladkov
2020-02-10 18:29 ` Andy Lutomirski
2020-02-12 16:03 ` Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 11/11] proc: Move hidepid values to uapi as they are user interface to mount Alexey Gladkov
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