All of lore.kernel.org
 help / color / mirror / Atom feed
From: ebiederm@xmission.com (Eric W. Biederman)
To: <linux-kernel@vger.kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	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>,
	Akinobu Mita <akinobu.mita@gmail.com>,
	Alexey Dobriyan <adobriyan@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>,
	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>,
	Oleg Nesterov <oleg@redhat.com>,
	Alexey Gladkov <gladkov.alexey@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Jeff Dike <jdike@addtoit.com>,
	Richard Weinberger <richard@nod.at>,
	Anton Ivanov <anton.ivanov@cambridgegreys.com>
Subject: [PATCH 1/3] uml: Don't consult current to find the proc_mnt in mconsole_proc
Date: Fri, 28 Feb 2020 14:18:14 -0600	[thread overview]
Message-ID: <8736ausby1.fsf_-_@x220.int.ebiederm.org> (raw)
In-Reply-To: <878skmsbyy.fsf_-_@x220.int.ebiederm.org> (Eric W. Biederman's message of "Fri, 28 Feb 2020 14:17:41 -0600")


Inspection of the control flow reveals that mconsole_proc is either
called from mconsole_stop called from mc_work_proc or from
mc_work_proc directly.  The function mc_work_proc is dispatched to a
kernel thread with schedule_work.

All of the threads that run dispatched by schedule_work are in the
init pid namespace.

So make the code clearer and by using init_pid_ns instead of
task_active_pid_ns(current).

Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 arch/um/drivers/mconsole_kern.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index b80a1d616e4e..e8f5c81c2c6c 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -123,7 +123,7 @@ void mconsole_log(struct mc_request *req)
 
 void mconsole_proc(struct mc_request *req)
 {
-	struct vfsmount *mnt = task_active_pid_ns(current)->proc_mnt;
+	struct vfsmount *mnt = init_pid_ns.proc_mnt;
 	char *buf;
 	int len;
 	struct file *file;
-- 
2.25.0


  reply	other threads:[~2020-02-28 20:20 UTC|newest]

Thread overview: 176+ 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 ` 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 15:05   ` Alexey Gladkov
2020-02-10 18:23   ` Andy Lutomirski
2020-02-10 18:23     ` Andy Lutomirski
2020-02-10 18:23     ` Andy Lutomirski
2020-02-12 15:00     ` Alexey Gladkov
2020-02-12 15:00       ` Alexey Gladkov
2020-02-10 15:05 ` [PATCH v8 04/11] proc: move hide_pid, pid_gid from pid_namespace " Alexey Gladkov
2020-02-10 15:05   ` Alexey Gladkov
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
2020-02-10 18:30     ` Andy Lutomirski
2020-02-10 18:30     ` Andy Lutomirski
2020-02-12 14:57     ` Alexey Gladkov
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   ` 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 17:46     ` Linus Torvalds
2020-02-10 17:46     ` Linus Torvalds
2020-02-10 19:23     ` Al Viro
2020-02-10 19:23       ` Al Viro
2020-02-11  1:36   ` Eric W. Biederman
2020-02-11  1:36     ` Eric W. Biederman
2020-02-11  1:36     ` Eric W. Biederman
2020-02-11  4:01     ` Eric W. Biederman
2020-02-11  4:01       ` Eric W. Biederman
2020-02-11  4:01       ` Eric W. Biederman
2020-02-12 14:49     ` Alexey Gladkov
2020-02-12 14:49       ` Alexey Gladkov
2020-02-12 14:59       ` Eric W. Biederman
2020-02-12 14:59         ` Eric W. Biederman
2020-02-12 14:59         ` Eric W. Biederman
2020-02-12 17:08         ` Alexey Gladkov
2020-02-12 17:08           ` Alexey Gladkov
2020-02-12 18:45         ` Linus Torvalds
2020-02-12 18:45           ` Linus Torvalds
2020-02-12 18:45           ` Linus Torvalds
2020-02-12 19:16           ` Eric W. Biederman
2020-02-12 19:16             ` Eric W. Biederman
2020-02-12 19:16             ` Eric W. Biederman
2020-02-12 19:49             ` Linus Torvalds
2020-02-12 19:49               ` Linus Torvalds
2020-02-12 19:49               ` Linus Torvalds
2020-02-12 20:03               ` Al Viro
2020-02-12 20:03                 ` Al Viro
2020-02-12 20:35                 ` Linus Torvalds
2020-02-12 20:35                   ` Linus Torvalds
2020-02-12 20:35                   ` Linus Torvalds
2020-02-12 20:38                   ` Al Viro
2020-02-12 20:38                     ` Al Viro
2020-02-12 20:41                     ` Al Viro
2020-02-12 20:41                       ` Al Viro
2020-02-12 21:02                       ` Linus Torvalds
2020-02-12 21:02                         ` Linus Torvalds
2020-02-12 21:02                         ` Linus Torvalds
2020-02-12 21:46                         ` Eric W. Biederman
2020-02-12 21:46                           ` Eric W. Biederman
2020-02-12 21:46                           ` Eric W. Biederman
2020-02-13  0:48                           ` Linus Torvalds
2020-02-13  0:48                             ` Linus Torvalds
2020-02-13  0:48                             ` Linus Torvalds
2020-02-13  4:37                             ` Eric W. Biederman
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 21:30                                   ` Linus Torvalds
2020-02-13 22:23                                   ` Al Viro
2020-02-13 22:47                                     ` Linus Torvalds
2020-02-13 22:47                                       ` Linus Torvalds
2020-02-14 14:15                                       ` Eric W. Biederman
2020-02-14 14:15                                         ` Eric W. Biederman
2020-02-14  3:48                                 ` 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 20:46                                 ` 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 20:47                                   ` 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 20:48                                   ` 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 20:49                                   ` Eric W. Biederman
2020-02-20 22:33                                   ` Linus Torvalds
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 20:49                                   ` Eric W. Biederman
2020-02-20 22:43                                   ` Linus Torvalds
2020-02-20 22:43                                     ` Linus Torvalds
2020-02-20 22:54                                   ` Al Viro
2020-02-20 23:00                                     ` Linus Torvalds
2020-02-20 23:00                                       ` Linus Torvalds
2020-02-20 23:03                                     ` Al Viro
2020-02-20 23:39                                       ` Eric W. Biederman
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 20:51                                   ` 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                                   ` 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
2020-02-20 20:52                                   ` Eric W. Biederman
2020-02-21 16:50                                   ` Oleg Nesterov
2020-02-22 15:46                                     ` Eric W. Biederman
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 23:02                                   ` Linus Torvalds
2020-02-20 23:07                                   ` Al Viro
2020-02-20 23:37                                     ` Eric W. Biederman
2020-02-20 23:37                                       ` Eric W. Biederman
2020-02-24 16:25                                 ` [PATCH v2 0/6] " Eric W. Biederman
2020-02-24 16:25                                   ` 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 16:26                                     ` 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                                     ` 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 16:27                                     ` 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                                     ` 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 16:28                                     ` 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
2020-02-24 16:29                                     ` Eric W. Biederman
2020-02-28 20:17                                   ` [PATCH 0/3] proc: Actually honor the mount options Eric W. Biederman
2020-02-28 20:17                                     ` Eric W. Biederman
2020-02-28 20:18                                     ` Eric W. Biederman [this message]
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 20:18                                       ` Eric W. Biederman
2020-02-28 20:30                                       ` Christian Brauner
2020-02-28 21:28                                         ` Eric W. Biederman
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 20:19                                       ` Eric W. Biederman
2020-02-28 20:39                                       ` Christian Brauner
2020-02-28 21:40                                         ` Eric W. Biederman
2020-02-28 21:40                                           ` Eric W. Biederman
2020-02-29  3:25                                       ` kbuild test robot
2020-02-29  3:25                                         ` kbuild test robot
2020-02-29  4:49                                         ` Eric W. Biederman
2020-02-29  4:49                                           ` Eric W. Biederman
2020-03-02 23:01                                           ` [kbuild-all] " Philip Li
2020-03-02 23:01                                             ` Philip Li
2020-03-12  2:03                                           ` [kbuild-all] " Li Zhijian
2020-03-12  2:03                                             ` Li Zhijian
2020-02-29  4:23                                       ` kbuild test robot
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
2020-02-28 22:34                                       ` 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
2020-02-14  3:49                       ` Eric W. Biederman
2020-02-12 19:47           ` Al Viro
2020-02-12 19:47             ` Al Viro
2020-02-11 22:45   ` Al Viro
2020-02-11 22:45     ` Al Viro
2020-02-12 14:26     ` Alexey Gladkov
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
2020-02-10 16:29     ` Jordan Glover
2020-02-12 14:34     ` Alexey Gladkov
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
2020-02-10 18:29     ` Andy Lutomirski
2020-02-10 18:29     ` Andy Lutomirski
2020-02-12 16:03     ` Alexey Gladkov
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=8736ausby1.fsf_-_@x220.int.ebiederm.org \
    --to=ebiederm@xmission.com \
    --cc=adobriyan@gmail.com \
    --cc=akinobu.mita@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=anton.ivanov@cambridgegreys.com \
    --cc=bfields@fieldses.org \
    --cc=corbet@lwn.net \
    --cc=danielmicay@gmail.com \
    --cc=gladkov.alexey@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jdike@addtoit.com \
    --cc=jlayton@poochiereds.net \
    --cc=keescook@chromium.org \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=ldv@altlinux.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=richard@nod.at \
    --cc=tixxdz@gmail.com \
    --cc=torvalds@linux-foundation.org \
    --cc=viro@zeniv.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.