linux-audit.redhat.com archive mirror
 help / color / mirror / Atom feed
From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
	linux-audit@redhat.com, linux-kernel@vger.kernel.org,
	Peter Hurley <peter@hurleysoftware.com>
Subject: [RESEND][PATCH 10/15] tty: audit: Remove false memory optimization
Date: Sat,  9 Jan 2016 20:59:03 -0800	[thread overview]
Message-ID: <1452401948-30790-11-git-send-email-peter@hurleysoftware.com> (raw)
In-Reply-To: <1452401948-30790-1-git-send-email-peter@hurleysoftware.com>

The tty audit buffer is allocated at first use and not freed until
the process exits. If tty audit is turned off after the audit buffer
has been allocated, no effort is made to release the buffer.
So re-checking if tty audit has just been turned off when tty audit
was just on is false optimization; the likelihood of triggering this
condition is exceedingly small.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
 drivers/tty/tty_audit.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
index 3d90f88..7943984 100644
--- a/drivers/tty/tty_audit.c
+++ b/drivers/tty/tty_audit.c
@@ -200,8 +200,7 @@ int tty_audit_push(void)
  *	tty_audit_buf_get	-	Get an audit buffer.
  *
  *	Get an audit buffer, allocate it if necessary.  Return %NULL
- *	if TTY auditing is disabled or out of memory.  Otherwise, return a new
- *	reference to the buffer.
+ *	if out of memory.  Otherwise, return a new reference to the buffer.
  */
 static struct tty_audit_buf *tty_audit_buf_get(void)
 {
@@ -224,9 +223,6 @@ static struct tty_audit_buf *tty_audit_buf_get(void)
 		return NULL;
 	}
 
-	if (~current->signal->audit_tty & AUDIT_TTY_ENABLE)
-		goto out;
-
 	spin_lock_irqsave(&current->sighand->siglock, flags);
 	buf = current->signal->tty_audit_buf;
 	if (!buf) {
-- 
2.7.0

  parent reply	other threads:[~2016-01-10  4:59 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-11  2:05 [PATCH 00/15] Rework tty audit Peter Hurley
2015-11-11  2:05 ` [PATCH 01/15] tty: audit: Early-out pty master reads earlier Peter Hurley
2015-11-11  2:05 ` [PATCH 02/15] tty: audit: Never audit packet mode Peter Hurley
2015-11-11  2:05 ` [PATCH 03/15] tty: audit: Remove icanon mode from call chain Peter Hurley
2015-11-12 19:10   ` Richard Guy Briggs
2015-11-12 19:58     ` Peter Hurley
2015-11-13  2:15       ` Richard Guy Briggs
2015-11-13  2:27         ` Peter Hurley
2015-11-13  3:28           ` Richard Guy Briggs
2015-11-16 13:25             ` Peter Hurley
2015-11-11  2:05 ` [PATCH 04/15] tty: audit: Defer audit buffer association Peter Hurley
2015-11-11  2:05 ` [PATCH 05/15] tty: audit: Take siglock directly Peter Hurley
2015-11-11  2:05 ` [PATCH 06/15] tty: audit: Ignore current association for audit push Peter Hurley
2015-11-11  2:05 ` [PATCH 07/15] tty: audit: Combine push functions Peter Hurley
2015-11-11  2:05 ` [PATCH 08/15] tty: audit: Track tty association with dev_t Peter Hurley
2015-11-11  2:05 ` [PATCH 09/15] tty: audit: Handle tty audit enable atomically Peter Hurley
2015-11-11  2:05 ` [PATCH 10/15] tty: audit: Remove false memory optimization Peter Hurley
2015-11-11  2:05 ` [PATCH 11/15] tty: audit: Remove tty_audit_buf reference counting Peter Hurley
2015-11-11  2:05 ` [PATCH 12/15] tty: audit: Simplify first-use allocation Peter Hurley
2015-11-11  2:05 ` [PATCH 13/15] tty: audit: Check audit enable first Peter Hurley
2015-11-11  2:05 ` [PATCH 14/15] tty: audit: Always push audit buffer before TIOCSTI Peter Hurley
2015-11-11  2:06 ` [PATCH 15/15] tty: audit: Poison tty_audit_buf while process exits Peter Hurley
2015-11-13  2:31 ` [PATCH 00/15] Rework tty audit Peter Hurley
2015-12-21  0:39 ` Paul Moore
2016-01-10  4:58 ` [RESEND][PATCH " Peter Hurley
2016-01-10  4:58   ` [RESEND][PATCH 01/15] tty: audit: Early-out pty master reads earlier Peter Hurley
2016-01-10  4:58   ` [RESEND][PATCH 02/15] tty: audit: Never audit packet mode Peter Hurley
2016-01-10  4:58   ` [RESEND][PATCH 03/15] tty: audit: Remove icanon mode from call chain Peter Hurley
2016-01-10  4:58   ` [RESEND][PATCH 04/15] tty: audit: Defer audit buffer association Peter Hurley
2016-01-10  4:58   ` [RESEND][PATCH 05/15] tty: audit: Take siglock directly Peter Hurley
2016-01-10  4:58   ` [RESEND][PATCH 06/15] tty: audit: Ignore current association for audit push Peter Hurley
2016-01-10  5:36     ` kbuild test robot
2016-01-10  7:00       ` Peter Hurley
2016-01-10  4:59   ` [RESEND][PATCH 07/15] tty: audit: Combine push functions Peter Hurley
2016-01-10  4:59   ` [RESEND][PATCH 08/15] tty: audit: Track tty association with dev_t Peter Hurley
2016-01-10  4:59   ` [RESEND][PATCH 09/15] tty: audit: Handle tty audit enable atomically Peter Hurley
2016-01-10  4:59   ` Peter Hurley [this message]
2016-01-10  4:59   ` [RESEND][PATCH 11/15] tty: audit: Remove tty_audit_buf reference counting Peter Hurley
2016-01-10  4:59   ` [RESEND][PATCH 12/15] tty: audit: Simplify first-use allocation Peter Hurley
2016-01-10  4:59   ` [RESEND][PATCH 13/15] tty: audit: Check audit enable first Peter Hurley
2016-01-10  4:59   ` [RESEND][PATCH 14/15] tty: audit: Always push audit buffer before TIOCSTI Peter Hurley
2016-01-10  4:59   ` [RESEND][PATCH 15/15] tty: audit: Poison tty_audit_buf while process exits Peter Hurley

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=1452401948-30790-11-git-send-email-peter@hurleysoftware.com \
    --to=peter@hurleysoftware.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.cz \
    --cc=linux-audit@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    /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).