[PATCH 4.9 043/240] media: gscpa/stv06xx: fix memory leak

Greg Kroah-Hartman
2021-05-20T11:04:59Z

From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

[ Upstream commit 4f4e6644cd876c844cdb3bea2dd7051787d5ae25 ]

For two of the supported sensors the stv06xx driver allocates memory which
is stored in sd->sensor_priv. This memory is freed on a disconnect, but if
the probe() fails, then it isn't freed and so this leaks memory.

Add a new probe_error() op that drivers can use to free any allocated
memory in case there was a probe failure.

Thanks to Pavel Skripkin <paskripkin@gmail.com> for discovering the cause
of the memory leak.

Reported-and-tested-by: syzbot+e7f4c64a4248a0340c37@syzkaller.appspotmail.com

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/usb/gspca/gspca.c | 2 ++
drivers/media/usb/gspca/gspca.h | 1 +
drivers/media/usb/gspca/stv06xx/stv06xx.c | 9 +++++++++
3 files changed, 12 insertions(+)

diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c
index d239075a6a65..79f1e8904e30 100644
--- a/drivers/media/usb/gspca/gspca.c
+++ b/drivers/media/usb/gspca/gspca.c
@@ -2146,6 +2146,8 @@ out:
#endif
v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
v4l2_device_unregister(&gspca_dev->v4l2_dev);
+ if (sd_desc->probe_error)
+ sd_desc->probe_error(gspca_dev);
kfree(gspca_dev->usb_buf);
kfree(gspca_dev);
return ret;
diff --git a/drivers/media/usb/gspca/gspca.h b/drivers/media/usb/gspca/gspca.h
index d39adf90303b..bec8fccc2c94 100644
--- a/drivers/media/usb/gspca/gspca.h
+++ b/drivers/media/usb/gspca/gspca.h
@@ -101,6 +101,7 @@ struct sd_desc {
cam_cf_op config; /* called on probe */
cam_op init; /* called on probe and resume */
cam_op init_controls; /* called on probe */
+ cam_v_op probe_error; /* called if probe failed, do cleanup here */
cam_op start; /* called on stream on after URBs creation */
cam_pkt_op pkt_scan;
/* optional operations */
diff --git a/drivers/media/usb/gspca/stv06xx/stv06xx.c b/drivers/media/usb/gspca/stv06xx/stv06xx.c
index 7d255529ed4c..40d4c99debb8 100644
--- a/drivers/media/usb/gspca/stv06xx/stv06xx.c
+++ b/drivers/media/usb/gspca/stv06xx/stv06xx.c
@@ -541,12 +541,21 @@ static int sd_int_pkt_scan(struct gspca_dev *gspca_dev,
static int stv06xx_config(struct gspca_dev *gspca_dev,
const struct usb_device_id *id);

+static void stv06xx_probe_error(struct gspca_dev *gspca_dev)
+{
+ struct sd *sd = (struct sd *)gspca_dev;
+
+ kfree(sd->sensor_priv);
+ sd->sensor_priv = NULL;
+}
+
/* sub-driver description */
static const struct sd_desc sd_desc = {
.name = MODULE_NAME,
.config = stv06xx_config,
.init = stv06xx_init,
.init_controls = stv06xx_init_controls,
+ .probe_error = stv06xx_probe_error,
.start = stv06xx_start,
.stopN = stv06xx_stopN,
.pkt_scan = stv06xx_pkt_scan,
--
2.30.2