[1/2,media] dib0700: fix locking in dib0700_i2c_xfer_new()

Commit Message

Dan Carpenter April 28, 2017, 12:52 p.m. UTC

This patch mostly adds unlocks to error paths.  But one additional small
change is that I made the first "break;" a "goto unlock;" which means
that now we return failure instead of success on that path.

Signed-off-by: Dan Carpenter <[e-mail]>

Patch

diff --git a/drivers/media/usb/dvb-usb/dib0700_core.c b/drivers/media/usb/dvb-usb/dib0700_core.c
index 08acdd32e412..4dea79718827 100644
--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -215,13 +215,14 @@  static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
 						 USB_CTRL_GET_TIMEOUT);
 			if (result < 0) {
 				deb_info("i2c read error (status = %d)\n", result);
-				break;
+				goto unlock;
 			}
 
 			if (msg[i].len > sizeof(st->buf)) {
 				deb_info("buffer too small to fit %d bytes\n",
 					 msg[i].len);
-				return -EIO;
+				result = -EIO;
+				goto unlock;
 			}
 
 			memcpy(msg[i].buf, st->buf, msg[i].len);
@@ -233,8 +234,8 @@  static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
 			/* Write request */
 			if (mutex_lock_interruptible(&d->usb_mutex) < 0) {
 				err("could not acquire lock");
-				mutex_unlock(&d->i2c_mutex);
-				return -EINTR;
+				result = -EINTR;
+				goto unlock;
 			}
 			st->buf[0] = REQUEST_NEW_I2C_WRITE;
 			st->buf[1] = msg[i].addr << 1;
@@ -247,7 +248,9 @@  static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
 			if (msg[i].len > sizeof(st->buf) - 4) {
 				deb_info("i2c message to big: %d\n",
 					 msg[i].len);
-				return -EIO;
+				mutex_unlock(&d->usb_mutex);
+				result = -EIO;
+				goto unlock;
 			}
 
 			/* The Actual i2c payload */
@@ -269,8 +272,11 @@  static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
 			}
 		}
 	}
+	result = i;
+
+unlock:
 	mutex_unlock(&d->i2c_mutex);
-	return i;
+	return result;
 }
 
 /*