Patchwork Hardy CVE: tty: Make tiocgicount a handler, CVE-2010-4076

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Submitter Tim Gardner
Date Feb. 18, 2011, 2:19 p.m.
Message ID <4D5E7FF2.3020506@canonical.com>
Download mbox | patch
Permalink /patch/83600/
State Accepted
Headers show

Comments

Tim Gardner - Feb. 18, 2011, 2:19 p.m.
Added CVE-2010-4077 and restored 'case TIOCGICOUNT' to its original code.
Stefan Bader - Feb. 18, 2011, 2:23 p.m.
On 02/18/2011 03:19 PM, Tim Gardner wrote:
> Added CVE-2010-4077 and restored 'case TIOCGICOUNT' to its original code.
> 
ACK (includes all later releases with just the cve number added. I am too lazy)
Brad Figg - Feb. 22, 2011, 4:27 p.m.
On 02/18/2011 06:19 AM, Tim Gardner wrote:
> Added CVE-2010-4077 and restored 'case TIOCGICOUNT' to its original code.
>

Acked-by: Brad Figg <brad.figg@canonical.com>

Patch

From 4a6899e11fed938ad6adec15e34019a8c8eb10ce Mon Sep 17 00:00:00 2001
From: Tim Gardner <tim.gardner@canonical.com>
Date: Wed, 16 Feb 2011 10:39:22 -0700
Subject: [PATCH] tty: Make tiocgicount a handler, CVE-2010-4076, CVE-2010-4077

BugLink: http://bugs.launchpad.net/bugs/720189

CVE-2010-4076
CVE-2010-4077

Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.

This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

(backported from commit d281da7ff6f70efca0553c288bb883e8605b3862)

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 .../openvz/patchset/0001-2.6.24-ovz002.patch       |   22 +++++++-----
 drivers/char/tty_io.c                              |   22 ++++++++++++
 drivers/serial/serial_core.c                       |   37 +++++++++-----------
 drivers/usb/serial/usb-serial.c                    |   13 +++++++
 include/linux/tty_driver.h                         |   11 ++++++
 include/linux/usb/serial.h                         |    2 +
 6 files changed, 78 insertions(+), 29 deletions(-)

diff --git a/debian/binary-custom.d/openvz/patchset/0001-2.6.24-ovz002.patch b/debian/binary-custom.d/openvz/patchset/0001-2.6.24-ovz002.patch
index f8443e0..729b278 100644
--- a/debian/binary-custom.d/openvz/patchset/0001-2.6.24-ovz002.patch
+++ b/debian/binary-custom.d/openvz/patchset/0001-2.6.24-ovz002.patch
@@ -4639,15 +4639,6 @@  Index: kernel/drivers/char/tty_io.c
 ===================================================================
 --- kernel.orig/drivers/char/tty_io.c	2008-11-18 01:19:43.000000000 +0100
 +++ kernel/drivers/char/tty_io.c	2008-11-24 15:47:45.000000000 +0100
-@@ -94,6 +94,8 @@
- #include <linux/wait.h>
- #include <linux/bitops.h>
- #include <linux/delay.h>
-+#include <linux/nsproxy.h>
-+#include <linux/ve.h>
- 
- #include <asm/uaccess.h>
- #include <asm/system.h>
 @@ -104,6 +106,7 @@
  
  #include <linux/kmod.h>
@@ -91574,3 +91565,16 @@  Index: kernel/sound/core/info.c
  	}
  	return 0;
  }
+diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
+index e85486b..8171d69 100644
+--- a/drivers/char/tty_io.c
++++ b/drivers/char/tty_io.c
+@@ -94,6 +94,8 @@
+ #include <linux/wait.h>
+ #include <linux/bitops.h>
+ #include <linux/delay.h>
++#include <linux/nsproxy.h>
++#include <linux/ve.h>
+ #include <linux/serial.h>
+ 
+ #include <asm/uaccess.h>
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 23d7cfd..4f29a78 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -94,6 +94,7 @@ 
 #include <linux/wait.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
+#include <linux/serial.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -3302,6 +3303,20 @@  static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
 	return retval;
 }
 
+static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
+{
+	int retval = -EINVAL;
+	struct serial_icounter_struct icount;
+	memset(&icount, 0, sizeof(icount));
+	if (tty->driver->get_icount)
+		retval = tty->driver->get_icount(tty, &icount);
+	if (retval != 0)
+		return retval;
+	if (copy_to_user(arg, &icount, sizeof(icount)))
+		return -EFAULT;
+	return 0;
+}
+
 /*
  * Split this up, as gcc can choke on it otherwise..
  */
@@ -3435,6 +3450,12 @@  int tty_ioctl(struct inode * inode, struct file * file,
 		case TIOCMBIC:
 		case TIOCMBIS:
 			return tty_tiocmset(tty, file, cmd, p);
+		case TIOCGICOUNT:
+			retval = tty_tiocgicount(tty, p);
+			/* For the moment allow fall through to the old method */
+			if (retval != -EINVAL)
+				return retval;
+			break;
 		case TCFLSH:
 			switch (arg) {
 			case TCIFLUSH:
@@ -3849,6 +3870,7 @@  void tty_set_operations(struct tty_driver *driver,
 	driver->write_proc = op->write_proc;
 	driver->tiocmget = op->tiocmget;
 	driver->tiocmset = op->tiocmset;
+	driver->get_icount = op->get_icount;
 }
 
 
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 3bb5d24..472a098 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1022,10 +1022,10 @@  uart_wait_modem_status(struct uart_state *state, unsigned long arg)
  * NB: both 1->0 and 0->1 transitions are counted except for
  *     RI where only 0->1 is counted.
  */
-static int uart_get_count(struct uart_state *state,
-			  struct serial_icounter_struct __user *icnt)
+static int uart_get_icount(struct tty_struct *tty,
+			  struct serial_icounter_struct *icount)
 {
-	struct serial_icounter_struct icount;
+	struct uart_state *state = tty->driver_data;
 	struct uart_icount cnow;
 	struct uart_port *port = state->port;
 
@@ -1033,19 +1033,19 @@  static int uart_get_count(struct uart_state *state,
 	memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
 	spin_unlock_irq(&port->lock);
 
-	icount.cts         = cnow.cts;
-	icount.dsr         = cnow.dsr;
-	icount.rng         = cnow.rng;
-	icount.dcd         = cnow.dcd;
-	icount.rx          = cnow.rx;
-	icount.tx          = cnow.tx;
-	icount.frame       = cnow.frame;
-	icount.overrun     = cnow.overrun;
-	icount.parity      = cnow.parity;
-	icount.brk         = cnow.brk;
-	icount.buf_overrun = cnow.buf_overrun;
-
-	return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
+	icount->cts         = cnow.cts;
+	icount->dsr         = cnow.dsr;
+	icount->rng         = cnow.rng;
+	icount->dcd         = cnow.dcd;
+	icount->rx          = cnow.rx;
+	icount->tx          = cnow.tx;
+	icount->frame       = cnow.frame;
+	icount->overrun     = cnow.overrun;
+	icount->parity      = cnow.parity;
+	icount->brk         = cnow.brk;
+	icount->buf_overrun = cnow.buf_overrun;
+
+	return 0;
 }
 
 /*
@@ -1098,10 +1098,6 @@  uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
 	case TIOCMIWAIT:
 		ret = uart_wait_modem_status(state, arg);
 		break;
-
-	case TIOCGICOUNT:
-		ret = uart_get_count(state, uarg);
-		break;
 	}
 
 	if (ret != -ENOIOCTLCMD)
@@ -2197,6 +2193,7 @@  static const struct tty_operations uart_ops = {
 #endif
 	.tiocmget	= uart_tiocmget,
 	.tiocmset	= uart_tiocmset,
+	.get_icount	= uart_get_icount,
 };
 
 /**
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index d7fae72..11bb54e 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -540,6 +540,18 @@  static int serial_tiocmset (struct tty_struct *tty, struct file *file,
 	return -EINVAL;
 }
 
+static int serial_get_icount(struct tty_struct *tty,
+				struct serial_icounter_struct *icount)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	dbg("%s - port %d", __func__, port->number);
+
+	if (port->serial->type->get_icount)
+		return port->serial->type->get_icount(tty, icount);
+	return -EINVAL;
+}
+
 /*
  * We would be calling tty_wakeup here, but unfortunately some line
  * disciplines have an annoying habit of calling tty->write from
@@ -1145,6 +1157,7 @@  static const struct tty_operations serial_ops = {
 	.read_proc =		serial_read_proc,
 	.tiocmget =		serial_tiocmget,
 	.tiocmset =		serial_tiocmset,
+	.get_icount = 		serial_get_icount,
 };
 
 struct tty_driver *usb_serial_tty_driver;
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 85c95cd..3ddb342 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -118,11 +118,18 @@ 
  *
  * 	This routine is used to send a high-priority XON/XOFF
  * 	character to the device.
+ *
+ * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount);
+ *
+ *	Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
+ *	structure to complete. This method is optional and will only be called
+ *	if provided (otherwise EINVAL will be returned).
  */
 
 #include <linux/fs.h>
 #include <linux/list.h>
 #include <linux/cdev.h>
+#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
 
 struct tty_struct;
 
@@ -157,6 +164,8 @@  struct tty_operations {
 	int (*tiocmget)(struct tty_struct *tty, struct file *file);
 	int (*tiocmset)(struct tty_struct *tty, struct file *file,
 			unsigned int set, unsigned int clear);
+	int (*get_icount)(struct tty_struct *tty,
+				struct serial_icounter_struct *icount);
 };
 
 struct tty_driver {
@@ -220,6 +229,8 @@  struct tty_driver {
 	int (*tiocmget)(struct tty_struct *tty, struct file *file);
 	int (*tiocmset)(struct tty_struct *tty, struct file *file,
 			unsigned int set, unsigned int clear);
+	int (*get_icount)(struct tty_struct *tty,
+				struct serial_icounter_struct *icount);
 
 	struct list_head tty_drivers;
 };
diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 488ce12..6f44a59 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -243,6 +243,8 @@  struct usb_serial_driver {
 	void (*unthrottle)	(struct usb_serial_port *port);
 	int  (*tiocmget)	(struct usb_serial_port *port, struct file *file);
 	int  (*tiocmset)	(struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
+	int  (*get_icount)(struct tty_struct *tty,
+			struct serial_icounter_struct *icount);
 
 	void (*read_int_callback)(struct urb *urb);
 	void (*write_int_callback)(struct urb *urb);
-- 
1.7.0.4