6 files changed, 40 insertions, 11 deletions

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index b1ec202099b2..b74de014cef1 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -165,15 +165,29 @@ static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
 	return put_user(x, ptr);
 }
 
+/* If we are not echoing the data, perhaps this is a secret so erase it */
+static inline void zero_buffer(struct tty_struct *tty, u8 *buffer, int size)
+{
+	bool icanon = !!L_ICANON(tty);
+	bool no_echo = !L_ECHO(tty);
+
+	if (icanon && no_echo)
+		memset(buffer, 0x00, size);
+}
+
 static inline int tty_copy_to_user(struct tty_struct *tty,
 					void __user *to,
-					const void *from,
+					void *from,
 					unsigned long n)
 {
 	struct n_tty_data *ldata = tty->disc_data;
+	int retval;
 
 	tty_audit_add_data(tty, from, n, ldata->icanon);
-	return copy_to_user(to, from, n);
+	retval = copy_to_user(to, from, n);
+	if (!retval)
+		zero_buffer(tty, from, n);
+	return retval;
 }
 
 /**
@@ -2005,6 +2019,7 @@ static int copy_from_read_buf(struct tty_struct *tty,
 		is_eof = n == 1 && read_buf(ldata, tail) == EOF_CHAR(tty);
 		tty_audit_add_data(tty, read_buf_addr(ldata, tail), n,
 				ldata->icanon);
+		zero_buffer(tty, read_buf_addr(ldata, tail), n);
 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
 		/* Turn single EOF into zero-length read */
 		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
index a260cde743e2..2db68dfe497d 100644
--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -133,6 +133,11 @@ static void kgdboc_unregister_kbd(void)
 
 static int kgdboc_option_setup(char *opt)
 {
+	if (!opt) {
+		pr_err("kgdboc: config string not provided\n");
+		return -EINVAL;
+	}
+
 	if (strlen(opt) >= MAX_CONFIG_LEN) {
 		printk(KERN_ERR "kgdboc: config string too long\n");
 		return -ENOSPC;
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 7d5ee8a13ac6..17a22073d226 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -648,7 +648,7 @@ static void sc16is7xx_handle_tx(struct uart_port *port)
 		uart_write_wakeup(port);
 }
 
-static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
+static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 {
 	struct uart_port *port = &s->p[portno].port;
 
@@ -657,7 +657,7 @@ static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 
 		iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
 		if (iir & SC16IS7XX_IIR_NO_INT_BIT)
-			break;
+			return false;
 
 		iir &= SC16IS7XX_IIR_ID_MASK;
 
@@ -685,16 +685,23 @@ static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 					    port->line, iir);
 			break;
 		}
-	} while (1);
+	} while (0);
+	return true;
 }
 
 static void sc16is7xx_ist(struct kthread_work *ws)
 {
 	struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work);
-	int i;
 
-	for (i = 0; i < s->devtype->nr_uart; ++i)
-		sc16is7xx_port_irq(s, i);
+	while (1) {
+		bool keep_polling = false;
+		int i;
+
+		for (i = 0; i < s->devtype->nr_uart; ++i)
+			keep_polling |= sc16is7xx_port_irq(s, i);
+		if (!keep_polling)
+			break;
+	}
 }
 
 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 8f3566cde3eb..355e9cad680d 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -454,6 +454,8 @@ receive_buf(struct tty_struct *tty, struct tty_buffer *head, int count)
 		if (count && disc->ops->receive_buf)
 			disc->ops->receive_buf(tty, p, f, count);
 	}
+	if (count > 0)
+		memset(p, 0, count);
 	return count;
 }
 
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 198451fa9e5d..c1cff2b455ae 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -357,7 +357,7 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line)
 	mutex_lock(&tty_mutex);
 	/* Search through the tty devices to look for a match */
 	list_for_each_entry(p, &tty_drivers, tty_drivers) {
-		if (strncmp(name, p->name, len) != 0)
+		if (!len || strncmp(name, p->name, len) != 0)
 			continue;
 		stp = str;
 		if (*stp == ',')
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 1445dd39aa62..bece7e39f512 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -330,7 +330,7 @@ speed_t tty_termios_baud_rate(struct ktermios *termios)
 		else
 			cbaud += 15;
 	}
-	return baud_table[cbaud];
+	return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
 }
 EXPORT_SYMBOL(tty_termios_baud_rate);
 
@@ -366,7 +366,7 @@ speed_t tty_termios_input_baud_rate(struct ktermios *termios)
 		else
 			cbaud += 15;
 	}
-	return baud_table[cbaud];
+	return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
 #else
 	return tty_termios_baud_rate(termios);
 #endif