Em Sat, 27 Feb 2021 02:37:31 +0300
Pavel Skripkin <paskripkin@xxxxxxxxx> escreveu:
> Syzbot reported memory leak in hdcs_probe_1x00()[1].
> hdcs_probe_1x00() allocates memory for struct hdcs, but if hdcs_init() fails in gspca_dev_probe2()
> this memory becomes leaked.
>
> int gspca_dev_probe2(struct usb_interface *intf,
> const struct usb_device_id *id,
> const struct sd_desc *sd_desc,
> int dev_size,
> struct module *module)
> {
> ...
>
> ret = sd_desc->config(gspca_dev, id);
> if (ret < 0)
> goto out;
> ret = sd_desc->init(gspca_dev);
> if (ret < 0)
> goto out;
> ...
> out:
> if (gspca_dev->input_dev)
> input_unregister_device(gspca_dev->input_dev);
> v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
> v4l2_device_unregister(&gspca_dev->v4l2_dev);
> kfree(gspca_dev->usb_buf);
> kfree(gspca_dev);
> return ret;
> }
>
> Reported-by: syzbot+e7f4c64a4248a0340c37@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
> Change-Id: Ia198671177ee346de61780813025110c7c491d7a
> ---
> drivers/media/usb/gspca/stv06xx/stv06xx_hdcs.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/usb/gspca/stv06xx/stv06xx_hdcs.c b/drivers/media/usb/gspca/stv06xx/stv06xx_hdcs.c
> index 5a47dcbf1c8e..24df13b33a02 100644
> --- a/drivers/media/usb/gspca/stv06xx/stv06xx_hdcs.c
> +++ b/drivers/media/usb/gspca/stv06xx/stv06xx_hdcs.c
> @@ -485,7 +485,7 @@ static int hdcs_init(struct sd *sd)
> stv_bridge_init[i][1]);
> }
> if (err < 0)
> - return err;
> + goto error;
>
> /* sensor soft reset */
> hdcs_reset(sd);
> @@ -496,12 +496,12 @@ static int hdcs_init(struct sd *sd)
> stv_sensor_init[i][1]);
> }
> if (err < 0)
> - return err;
> + goto error;
>
> /* Enable continuous frame capture, bit 2: stop when frame complete */
> err = stv06xx_write_sensor(sd, HDCS_REG_CONFIG(sd), BIT(3));
> if (err < 0)
> - return err;
> + goto error;
>
> /* Set PGA sample duration
> (was 0x7E for the STV602, but caused slow framerate with HDCS-1020) */
> @@ -512,9 +512,13 @@ static int hdcs_init(struct sd *sd)
> err = stv06xx_write_sensor(sd, HDCS_TCTRL,
> (HDCS_ADC_START_SIG_DUR << 5) | hdcs->psmp);
> if (err < 0)
> - return err;
> + goto error;
>
> return hdcs_set_size(sd, hdcs->array.width, hdcs->array.height);
> +
> +error:
> + kfree(hdcs);
> + return err;
> }
This doesn't seem the right fix here, as it is not the _init function
that allocates it. Also, when the device is disconnected, a memory leak
will happen.
I suspect that the right fix would be to move this:
hdcs = kmalloc(sizeof(struct hdcs), GFP_KERNEL);
if (!hdcs)
return -ENOMEM;
To the main driver (stv06xx.c) - probably replacing it by kzalloc(),
and then handle the free code both both sd_probe() and sd_disconnect().
Thanks,
Mauro
