From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Matthew Garrett <matthewgarrett@google.com>,
James Morris James Morris <jmorris@namei.org>,
LSM List <linux-security-module@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>,
Ben Hutchings <ben@decadent.org.uk>,
Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH 7/7 v2] tracing: Do not create tracefs files if tracefs lockdown is in effect
Date: Fri, 11 Oct 2019 20:57:54 -0400 [thread overview]
Message-ID: <20191012005921.580293464@goodmis.org> (raw)
In-Reply-To: 20191012005747.210722465@goodmis.org
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
If on boot up, lockdown is activated for tracefs, don't even bother creating
the files. This can also prevent instances from being created if lockdown is
in effect.
Link: http://lkml.kernel.org/r/CAHk-=whC6Ji=fWnjh2+eS4b15TnbsS4VPVtvBOwCy1jjEG_JHQ@mail.gmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
fs/tracefs/inode.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index eeeae0475da9..0caa151cae4e 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -16,6 +16,7 @@
#include <linux/namei.h>
#include <linux/tracefs.h>
#include <linux/fsnotify.h>
+#include <linux/security.h>
#include <linux/seq_file.h>
#include <linux/parser.h>
#include <linux/magic.h>
@@ -390,6 +391,9 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
struct dentry *dentry;
struct inode *inode;
+ if (security_locked_down(LOCKDOWN_TRACEFS))
+ return NULL;
+
if (!(mode & S_IFMT))
mode |= S_IFREG;
BUG_ON(!S_ISREG(mode));
--
2.23.0
next prev parent reply other threads:[~2019-10-12 0:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-12 0:57 [PATCH 0/7 v2] tracing: Fix tracefs lockdown and various clean ups Steven Rostedt
2019-10-12 0:57 ` [PATCH 1/7 v2] tracefs: Revert ccbd54ff54e8 ("tracefs: Restrict tracefs when the kernel is locked down") Steven Rostedt
2019-10-12 22:56 ` Linus Torvalds
2019-10-13 0:35 ` Steven Rostedt
2019-10-13 0:39 ` Steven Rostedt
2019-10-12 0:57 ` [PATCH 2/7 v2] ftrace: Get a reference counter for the trace_array on filter files Steven Rostedt
2019-10-12 0:57 ` [PATCH 3/7 v2] tracing: Get trace_array reference for available_tracers files Steven Rostedt
2019-10-12 0:57 ` [PATCH 4/7 v2] tracing: Have trace events system open call tracing_open_generic_tr() Steven Rostedt
2019-10-12 2:09 ` Steven Rostedt
2019-10-12 0:57 ` [PATCH 5/7 v2] tracing: Add tracing_check_open_get_tr() Steven Rostedt
2019-10-12 0:57 ` [PATCH 6/7 v2] tracing: Add some more locked_down checks Steven Rostedt
2019-10-12 0:57 ` Steven Rostedt [this message]
2021-04-13 8:13 ` [PATCH 7/7 v2] tracing: Do not create tracefs files if tracefs lockdown is in effect Ondrej Mosnacek
2021-05-07 12:00 ` Ondrej Mosnacek
2021-05-07 13:26 ` Steven Rostedt
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=20191012005921.580293464@goodmis.org \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=ben@decadent.org.uk \
--cc=jmorris@namei.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=matthewgarrett@google.com \
--cc=mingo@kernel.org \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).