ptp: Fix some locking bugs in ptp_read()

In ptp_read there is an unlock missing on an error path, and a double unlock on another error path. Signed-off-by: Dan Carpenter <[email protected]> Acked-by: Richard Cochran <[email protected]> Signed-off-by: John Stultz <[email protected]>
oleg-nesterov · Jun 2, 2011 · fb5a18c · fb5a18c
1 parent e23ef22
commit fb5a18c
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
@@ -130,8 +130,10 @@ ssize_t ptp_read(struct posix_clock *pc,
 		return -ERESTARTSYS;
 	}
 
-	if (ptp->defunct)
+	if (ptp->defunct) {
+		mutex_unlock(&ptp->tsevq_mux);
 		return -ENODEV;
+	}
 
 	spin_lock_irqsave(&queue->lock, flags);
 
@@ -151,10 +153,8 @@ ssize_t ptp_read(struct posix_clock *pc,
 
 	mutex_unlock(&ptp->tsevq_mux);
 
-	if (copy_to_user(buf, event, cnt)) {
-		mutex_unlock(&ptp->tsevq_mux);
+	if (copy_to_user(buf, event, cnt))
 		return -EFAULT;
-	}
 
 	return cnt;
 }