media: dvb-usb: m920x: Fix a potential memory leak in m920x_i2c_xfer()

'read' is freed when it is known to be NULL, but not when a read error
occurs.

Revert the logic to avoid a small leak, should a m920x_read() call fail.

Fixes: a2ab06d7c4d6 ("media: m920x: don't use stack on USB reads")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

diff --git a/drivers/media/usb/dvb-usb/m920x.c b/drivers/media/usb/dvb-usb/m920x.c
index fea5bcf..c88a202 100644 (file)
--- a/drivers/media/usb/dvb-usb/m920x.c
+++ b/drivers/media/usb/dvb-usb/m920x.c
@@ -277,7 +277,6 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu
                        char *read = kmalloc(1, GFP_KERNEL);
                        if (!read) {
                                ret = -ENOMEM;
-                               kfree(read);
                                goto unlock;
                        }
 
@@ -288,8 +287,10 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu
 
                                if ((ret = m920x_read(d->udev, M9206_I2C, 0x0,
                                                      0x20 | stop,
-                                                     read, 1)) != 0)
+                                                     read, 1)) != 0) {
+                                       kfree(read);
                                        goto unlock;
+                               }
                                msg[i].buf[j] = read[0];
                        }