[PATCH] audit: add tty field to LOGIN event

[Richard Guy Briggs]

The tty field was missing from AUDIT_LOGIN events.

Refactor code to create a new function audit_get_tty(), using it to
replace the call in audit_log_task_info() and to add it to
audit_log_set_loginuid().

Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
---
 include/linux/audit.h |   18 ++++++++++++++++++
 kernel/audit.c        |   11 +----------
 kernel/auditsc.c      |    5 +++--
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index b40ed5d..20c6649 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -26,6 +26,7 @@
 #include <linux/sched.h>
 #include <linux/ptrace.h>
 #include <uapi/linux/audit.h>
+#include <linux/tty.h>
 
 #define AUDIT_INO_UNSET ((unsigned long)-1)
 #define AUDIT_DEV_UNSET ((dev_t)-1)
@@ -343,6 +344,19 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 	return tsk->sessionid;
 }
 
+static inline char *audit_get_tty(struct task_struct *tsk)
+{
+	char *tty;
+
+	spin_lock_irq(&tsk->sighand->siglock);
+	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
+		tty = tsk->signal->tty->name;
+	else
+		tty = "(none)";
+	spin_unlock_irq(&tsk->sighand->siglock);
+	return tty;
+}
+
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
 extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
 extern void __audit_bprm(struct linux_binprm *bprm);
@@ -500,6 +514,10 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 {
 	return -1;
 }
+static inline char *audit_get_tty(struct task_struct *tsk)
+{
+	return "(invalid)";
+}
 static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
 { }
 static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,
diff --git a/kernel/audit.c b/kernel/audit.c
index 3a3e5de..fae11df 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -64,7 +64,6 @@
 #include <linux/security.h>
 #endif
 #include <linux/freezer.h>
-#include <linux/tty.h>
 #include <linux/pid_namespace.h>
 #include <net/netns/generic.h>
 
@@ -1873,7 +1872,6 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 {
 	const struct cred *cred;
 	char comm[sizeof(tsk->comm)];
-	char *tty;
 
 	if (!ab)
 		return;
@@ -1881,13 +1879,6 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 	/* tsk == current */
 	cred = current_cred();
 
-	spin_lock_irq(&tsk->sighand->siglock);
-	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
-		tty = tsk->signal->tty->name;
-	else
-		tty = "(none)";
-	spin_unlock_irq(&tsk->sighand->siglock);
-
 	audit_log_format(ab,
 			 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
 			 " euid=%u suid=%u fsuid=%u"
@@ -1903,7 +1894,7 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 			 from_kgid(&init_user_ns, cred->egid),
 			 from_kgid(&init_user_ns, cred->sgid),
 			 from_kgid(&init_user_ns, cred->fsgid),
-			 tty, audit_get_sessionid(tsk));
+			 audit_get_tty(tsk), audit_get_sessionid(tsk));
 
 	audit_log_format(ab, " comm=");
 	audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 195ffae..a0467fb 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1993,8 +1993,9 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 		return;
 	audit_log_format(ab, "pid=%d uid=%u", task_pid_nr(current), uid);
 	audit_log_task_context(ab);
-	audit_log_format(ab, " old-auid=%u auid=%u old-ses=%u ses=%u res=%d",
-			 oldloginuid, loginuid, oldsessionid, sessionid, !rc);
+	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
+			 oldloginuid, loginuid, audit_get_tty(current),
+			 oldsessionid, sessionid, !rc);
 	audit_log_end(ab);
 }
 
-- 
1.7.1