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
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
next prev parent reply index
Thread overview: 85+ 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 ` [PATCH v8 04/11] proc: move hide_pid, pid_gid from pid_namespace " 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
2020-02-12 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 ` Eric W. Biederman [this message]
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
2020-02-28 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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