[media] dib0700: protect the dib0700 buffer access

This patch protects the common buffer access inside the dib0700 in order
to manage concurrent access. This protection is done using mutex.

Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Florian Mickler <florian@mickler.org>
Cc: stable@kernel.org
Signed-off-by: Javier Marcet <javier@marcet.info>
Signed-off-by: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Patrick Boettcher <patrick.boettcher@dibcom.fr>
[mchehab@redhat.com: dprint requires 3 arguments. Replaced by dib_info]
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 72 insertions, 9 deletions

diff --git a/drivers/media/dvb/dvb-usb/dib0700_core.c b/drivers/media/dvb/dvb-usb/dib0700_core.c
index 5eb91b4f8fd0..a224e94325b7 100644
--- a/drivers/media/dvb/dvb-usb/dib0700_core.c
+++ b/drivers/media/dvb/dvb-usb/dib0700_core.c
@@ -30,6 +30,11 @@ int dib0700_get_version(struct dvb_usb_device *d, u32 *hwversion,
         struct dib0700_state *st = d->priv;
         int ret;
 
+        if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                deb_info("could not acquire lock");
+                return 0;
+        }
+
         ret = usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0),
                                   REQUEST_GET_VERSION,
                                   USB_TYPE_VENDOR | USB_DIR_IN, 0, 0,
@@ -46,6 +51,7 @@ int dib0700_get_version(struct dvb_usb_device *d, u32 *hwversion,
         if (fwtype != NULL)
                 *fwtype     = (st->buf[12] << 24) | (st->buf[13] << 16) |
                         (st->buf[14] << 8) | st->buf[15];
+        mutex_unlock(&d->usb_mutex);
         return ret;
 }
 
@@ -108,7 +114,12 @@ int dib0700_ctrl_rd(struct dvb_usb_device *d, u8 *tx, u8 txlen, u8 *rx, u8 rxlen
 int dib0700_set_gpio(struct dvb_usb_device *d, enum dib07x0_gpios gpio, u8 gpio_dir, u8 gpio_val)
 {
         struct dib0700_state *st = d->priv;
-        s16 ret;
+        int ret;
+
+        if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                deb_info("could not acquire lock");
+                return 0;
+        }
 
         st->buf[0] = REQUEST_SET_GPIO;
         st->buf[1] = gpio;
@@ -116,6 +127,7 @@ int dib0700_set_gpio(struct dvb_usb_device *d, enum dib07x0_gpios gpio, u8 gpio_
 
         ret = dib0700_ctrl_wr(d, st->buf, 3);
 
+        mutex_unlock(&d->usb_mutex);
         return ret;
 }
 
@@ -125,6 +137,11 @@ static int dib0700_set_usb_xfer_len(struct dvb_usb_device *d, u16 nb_ts_packets)
         int ret;
 
         if (st->fw_version >= 0x10201) {
+                if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                        deb_info("could not acquire lock");
+                        return 0;
+                }
+
                 st->buf[0] = REQUEST_SET_USB_XFER_LEN;
                 st->buf[1] = (nb_ts_packets >> 8) & 0xff;
                 st->buf[2] = nb_ts_packets & 0xff;
@@ -132,6 +149,7 @@ static int dib0700_set_usb_xfer_len(struct dvb_usb_device *d, u16 nb_ts_packets)
                 deb_info("set the USB xfer len to %i Ts packet\n", nb_ts_packets);
 
                 ret = dib0700_ctrl_wr(d, st->buf, 3);
+                mutex_unlock(&d->usb_mutex);
         } else {
                 deb_info("this firmware does not allow to change the USB xfer len\n");
                 ret = -EIO;
@@ -208,6 +226,10 @@ static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
 
                 } else {
                         /* Write request */
+                        if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                                deb_info("could not acquire lock");
+                                return 0;
+                        }
                         st->buf[0] = REQUEST_NEW_I2C_WRITE;
                         st->buf[1] = msg[i].addr << 1;
                         st->buf[2] = (en_start << 7) | (en_stop << 6) |
@@ -227,6 +249,7 @@ static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
                                                  USB_TYPE_VENDOR | USB_DIR_OUT,
                                                  0, 0, st->buf, msg[i].len + 4,
                                                  USB_CTRL_GET_TIMEOUT);
+                        mutex_unlock(&d->usb_mutex);
                         if (result < 0) {
                                 deb_info("i2c write error (status = %d)\n", result);
                                 break;
@@ -249,6 +272,10 @@ static int dib0700_i2c_xfer_legacy(struct i2c_adapter *adap,
 
         if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
                 return -EAGAIN;
+        if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                deb_info("could not acquire lock");
+                return 0;
+        }
 
         for (i = 0; i < num; i++) {
                 /* fill in the address */
@@ -279,6 +306,7 @@ static int dib0700_i2c_xfer_legacy(struct i2c_adapter *adap,
                                 break;
                 }
         }
+        mutex_unlock(&d->usb_mutex);
         mutex_unlock(&d->i2c_mutex);
 
         return i;
@@ -337,7 +365,12 @@ static int dib0700_set_clock(struct dvb_usb_device *d, u8 en_pll,
         u16 pll_loopdiv, u16 free_div, u16 dsuScaler)
 {
         struct dib0700_state *st = d->priv;
-        s16 ret;
+        int ret;
+
+        if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                deb_info("could not acquire lock");
+                return 0;
+        }
 
         st->buf[0] = REQUEST_SET_CLOCK;
         st->buf[1] = (en_pll << 7) | (pll_src << 6) |
@@ -352,6 +385,7 @@ static int dib0700_set_clock(struct dvb_usb_device *d, u8 en_pll,
         st->buf[9] =  dsuScaler         & 0xff; /* LSB */
 
         ret = dib0700_ctrl_wr(d, st->buf, 10);
+        mutex_unlock(&d->usb_mutex);
 
         return ret;
 }
@@ -360,10 +394,16 @@ int dib0700_set_i2c_speed(struct dvb_usb_device *d, u16 scl_kHz)
 {
         struct dib0700_state *st = d->priv;
         u16 divider;
+        int ret;
 
         if (scl_kHz == 0)
                 return -EINVAL;
 
+        if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                deb_info("could not acquire lock");
+                return 0;
+        }
+
         st->buf[0] = REQUEST_SET_I2C_PARAM;
         divider = (u16) (30000 / scl_kHz);
         st->buf[1] = 0;
@@ -379,7 +419,11 @@ int dib0700_set_i2c_speed(struct dvb_usb_device *d, u16 scl_kHz)
         deb_info("setting I2C speed: %04x %04x %04x (%d kHz).",
                 (st->buf[2] << 8) | (st->buf[3]), (st->buf[4] << 8) |
                 st->buf[5], (st->buf[6] << 8) | st->buf[7], scl_kHz);
-        return dib0700_ctrl_wr(d, st->buf, 8);
+
+        ret = dib0700_ctrl_wr(d, st->buf, 8);
+        mutex_unlock(&d->usb_mutex);
+
+        return ret;
 }
 
 
@@ -515,6 +559,11 @@ int dib0700_streaming_ctrl(struct dvb_usb_adapter *adap, int onoff)
                 }
         }
 
+        if (mutex_lock_interruptible(&adap->dev->usb_mutex) < 0) {
+                deb_info("could not acquire lock");
+                return 0;
+        }
+
         st->buf[0] = REQUEST_ENABLE_VIDEO;
         /* this bit gives a kind of command,
          * rather than enabling something or not */
@@ -548,7 +597,10 @@ int dib0700_streaming_ctrl(struct dvb_usb_adapter *adap, int onoff)
 
         deb_info("data for streaming: %x %x\n", st->buf[1], st->buf[2]);
 
-        return dib0700_ctrl_wr(adap->dev, st->buf, 4);
+        ret = dib0700_ctrl_wr(adap->dev, st->buf, 4);
+        mutex_unlock(&adap->dev->usb_mutex);
+
+        return ret;
 }
 
 int dib0700_change_protocol(struct rc_dev *rc, u64 rc_type)
@@ -557,6 +609,11 @@ int dib0700_change_protocol(struct rc_dev *rc, u64 rc_type)
         struct dib0700_state *st = d->priv;
         int new_proto, ret;
 
+        if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
+                deb_info("could not acquire lock");
+                return 0;
+        }
+
         st->buf[0] = REQUEST_SET_RC;
         st->buf[1] = 0;
         st->buf[2] = 0;
@@ -567,23 +624,29 @@ int dib0700_change_protocol(struct rc_dev *rc, u64 rc_type)
         else if (rc_type == RC_TYPE_NEC)
                 new_proto = 0;
         else if (rc_type == RC_TYPE_RC6) {
-                if (st->fw_version < 0x10200)
-                        return -EINVAL;
+                if (st->fw_version < 0x10200) {
+                        ret = -EINVAL;
+                        goto out;
+                }
 
                 new_proto = 2;
-        } else
-                return -EINVAL;
+        } else {
+                ret = -EINVAL;
+                goto out;
+        }
 
         st->buf[1] = new_proto;
 
         ret = dib0700_ctrl_wr(d, st->buf, 3);
         if (ret < 0) {
                 err("ir protocol setup failed");
-                return ret;
+                goto out;
         }
 
         d->props.rc.core.protocol = rc_type;
 
+out:
+        mutex_unlock(&d->usb_mutex);
         return ret;
 }