Hi!
> From: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
>
> [ Upstream commit a2ab06d7c4d6bfd0b545a768247a70463e977e27 ]
>
> Using stack-allocated pointers for USB message data don't work.
> This driver is almost OK with that, except for the I2C read
> logic.
>
> Fix it by using a temporary read buffer, just like on all other
> calls to m920x_read().
This introduces memory leak... and I don't believe it really fixes the
problem.
> index eafc5c82467f4..5b806779e2106 100644
> --- a/drivers/media/usb/dvb-usb/m920x.c
> +++ b/drivers/media/usb/dvb-usb/m920x.c
> @@ -284,6 +284,13 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu
> /* Should check for ack here, if we knew how. */
> }
> if (msg[i].flags & I2C_M_RD) {
> + char *read = kmalloc(1, GFP_KERNEL);
> + if (!read) {
> + ret = -ENOMEM;
> + kfree(read);
> + goto unlock;
> + }
kfree(NULL);
> for (j = 0; j < msg[i].len; j++) {
> /* Last byte of transaction?
> * Send STOP, otherwise send ACK. */
> @@ -291,9 +298,12 @@ 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,
> - &msg[i].buf[j], 1)) != 0)
> + read, 1)) != 0)
> goto unlock;
Memory leak of read.
> + msg[i].buf[j] = read[0];
> }
> +
> + kfree(read);
> } else {
> for (j = 0; j < msg[i].len; j++) {
> /* Last byte of transaction? Then send STOP. */
But more importantly, do we have exact copy of the read problem just
below, during write?
Best regards,
Pavel
diff --git a/drivers/media/usb/dvb-usb/m920x.c b/drivers/media/usb/dvb-usb/m920x.c
index 691e05833db1..e5ee54324a28 100644
--- a/drivers/media/usb/dvb-usb/m920x.c
+++ b/drivers/media/usb/dvb-usb/m920x.c
@@ -250,7 +250,7 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu
{
struct dvb_usb_device *d = i2c_get_adapdata(adap);
int i, j;
- int ret = 0;
+ int ret;
if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
return -EAGAIN;
@@ -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];
}
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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