linux-kernel - [patch 1/1] selinux: fix tty locking

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1156425192.8506.167.camel@moss-spartans.epoch.ncsc.mil>
Date:	Thu, 24 Aug 2006 09:13:12 -0400
From:	Stephen Smalley <sds@...ho.nsa.gov>
To:	Andrew Morton <akpm@...l.org>
Cc:	lkml <linux-kernel@...r.kernel.org>,
	Eric Paris <eparis@...hat.com>,
	James Morris <jmorris@...ei.org>,
	Alan Cox <alan@...rguk.ukuu.org.uk>
Subject: [patch 1/1] selinux: fix tty locking

Take tty_mutex when accessing ->signal->tty in selinux code.
Noted by Alan Cox.  Longer term, we are looking at refactoring the code to provide better encapsulation of the tty layer, but this is a simple fix that addresses the immediate bug.

Signed-off-by:  Stephen Smalley <sds@...ho.nsa.gov>

---

 security/selinux/hooks.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5d1b8c7..4b0f904 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1711,10 +1711,12 @@ static inline void flush_unauthorized_fi
 {
 	struct avc_audit_data ad;
 	struct file *file, *devnull = NULL;
-	struct tty_struct *tty = current->signal->tty;
+	struct tty_struct *tty;
 	struct fdtable *fdt;
 	long j = -1;
 
+	mutex_lock(&tty_mutex);
+	tty = current->signal->tty;
 	if (tty) {
 		file_list_lock();
 		file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
@@ -1734,6 +1736,7 @@ static inline void flush_unauthorized_fi
 		}
 		file_list_unlock();
 	}
+	mutex_unlock(&tty_mutex);
 
 	/* Revalidate access to inherited open files. */
 

-- 
Stephen Smalley
National Security Agency

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/