audit: use spin_lock_irqsave/restore in audit tty code

Some of the callers of the audit tty function use spin_lock_irqsave/restore.
We were using the forced always enable version, which seems really bad.
Since I don't know every one of these code paths well enough, it makes
sense to just switch everything to the safe version.  Maybe it's a
little overzealous, but it's a lot better than an unlucky deadlock when
we return to a caller with irq enabled and they expect it to be
disabled.

Signed-off-by: Eric Paris <eparis@redhat.com>

2 files changed, 25 insertions, 17 deletions

diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
index ea2e5ad71731..755d418019c8 100644
--- a/drivers/tty/tty_audit.c
+++ b/drivers/tty/tty_audit.c
@@ -111,11 +111,12 @@ static void tty_audit_buf_push(struct tty_audit_buf *buf)
 void tty_audit_exit(void)
 {
         struct tty_audit_buf *buf;
+        unsigned long flags;
 
-        spin_lock_irq(&current->sighand->siglock);
+        spin_lock_irqsave(&current->sighand->siglock, flags);
         buf = current->signal->tty_audit_buf;
         current->signal->tty_audit_buf = NULL;
-        spin_unlock_irq(&current->sighand->siglock);
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
         if (!buf)
                 return;
 
@@ -133,9 +134,11 @@ void tty_audit_exit(void)
  */
 void tty_audit_fork(struct signal_struct *sig)
 {
-        spin_lock_irq(&current->sighand->siglock);
+        unsigned long flags;
+
+        spin_lock_irqsave(&current->sighand->siglock, flags);
         sig->audit_tty = current->signal->audit_tty;
-        spin_unlock_irq(&current->sighand->siglock);
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 }
 
 /**
@@ -145,13 +148,14 @@ void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 {
         struct tty_audit_buf *buf;
         int major, minor, should_audit;
+        unsigned long flags;
 
-        spin_lock_irq(&current->sighand->siglock);
+        spin_lock_irqsave(&current->sighand->siglock, flags);
         should_audit = current->signal->audit_tty;
         buf = current->signal->tty_audit_buf;
         if (buf)
                 atomic_inc(&buf->count);
-        spin_unlock_irq(&current->sighand->siglock);
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
         major = tty->driver->major;
         minor = tty->driver->minor_start + tty->index;
@@ -221,10 +225,11 @@ static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
                 unsigned icanon)
 {
         struct tty_audit_buf *buf, *buf2;
+        unsigned long flags;
 
         buf = NULL;
         buf2 = NULL;
-        spin_lock_irq(&current->sighand->siglock);
+        spin_lock_irqsave(&current->sighand->siglock, flags);
         if (likely(!current->signal->audit_tty))
                 goto out;
         buf = current->signal->tty_audit_buf;
@@ -232,7 +237,7 @@ static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
                 atomic_inc(&buf->count);
                 goto out;
         }
-        spin_unlock_irq(&current->sighand->siglock);
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
         buf2 = tty_audit_buf_alloc(tty->driver->major,
                                    tty->driver->minor_start + tty->index,
@@ -242,7 +247,7 @@ static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
                 return NULL;
         }
 
-        spin_lock_irq(&current->sighand->siglock);
+        spin_lock_irqsave(&current->sighand->siglock, flags);
         if (!current->signal->audit_tty)
                 goto out;
         buf = current->signal->tty_audit_buf;
@@ -254,7 +259,7 @@ static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
         atomic_inc(&buf->count);
         /* Fall through */
  out:
-        spin_unlock_irq(&current->sighand->siglock);
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
         if (buf2)
                 tty_audit_buf_free(buf2);
         return buf;
@@ -317,16 +322,17 @@ void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
 void tty_audit_push(struct tty_struct *tty)
 {
         struct tty_audit_buf *buf;
+        unsigned long flags;
 
-        spin_lock_irq(&current->sighand->siglock);
+        spin_lock_irqsave(&current->sighand->siglock, flags);
         if (likely(!current->signal->audit_tty)) {
-                spin_unlock_irq(&current->sighand->siglock);
+                spin_unlock_irqrestore(&current->sighand->siglock, flags);
                 return;
         }
         buf = current->signal->tty_audit_buf;
         if (buf)
                 atomic_inc(&buf->count);
-        spin_unlock_irq(&current->sighand->siglock);
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
         if (buf) {
                 int major, minor;
diff --git a/kernel/audit.c b/kernel/audit.c
index 44803f25b236..241aa8593fa8 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -804,10 +804,11 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         case AUDIT_TTY_GET: {
                 struct audit_tty_status s;
                 struct task_struct *tsk = current;
+                unsigned long flags;
 
-                spin_lock_irq(&tsk->sighand->siglock);
+                spin_lock_irqsave(&tsk->sighand->siglock, flags);
                 s.enabled = tsk->signal->audit_tty != 0;
-                spin_unlock_irq(&tsk->sighand->siglock);
+                spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 
                 audit_send_reply(NETLINK_CB(skb).portid, seq,
                                  AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
@@ -816,6 +817,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         case AUDIT_TTY_SET: {
                 struct audit_tty_status *s;
                 struct task_struct *tsk = current;
+                unsigned long flags;
 
                 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
                         return -EINVAL;
@@ -823,9 +825,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 if (s->enabled != 0 && s->enabled != 1)
                         return -EINVAL;
 
-                spin_lock_irq(&tsk->sighand->siglock);
+                spin_lock_irqsave(&tsk->sighand->siglock, flags);
                 tsk->signal->audit_tty = s->enabled != 0;
-                spin_unlock_irq(&tsk->sighand->siglock);
+                spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
                 break;
         }
         default: