linux-kernel - [PATCH] media: cpia2: fix memory leak in cpia2_usb

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Date:   Wed, 21 Apr 2021 22:43:45 +0300
From:   Pavel Skripkin <paskripkin@...il.com>
To:     mchehab@...nel.org, gustavoars@...nel.org
Cc:     linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
        Pavel Skripkin <paskripkin@...il.com>,
        syzbot+d1e69c888f0d3866ead4@...kaller.appspotmail.com
Subject: [PATCH] media: cpia2: fix memory leak in cpia2_usb_probe

syzbot reported leak in cpia2 usb driver. The problem was
in invalid error handling.

v4l2_device_register() is called in cpia2_init_camera_struct(), but
all error cases after cpia2_init_camera_struct() did not call the
v4l2_device_unregister()

Reported-by: syzbot+d1e69c888f0d3866ead4@...kaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@...il.com>
---
 drivers/media/usb/cpia2/cpia2.h      |  1 +
 drivers/media/usb/cpia2/cpia2_core.c | 12 ++++++++++++
 drivers/media/usb/cpia2/cpia2_usb.c  | 13 +++++++------
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/media/usb/cpia2/cpia2.h b/drivers/media/usb/cpia2/cpia2.h
index 50835f5f7512..57b7f1ea68da 100644
--- a/drivers/media/usb/cpia2/cpia2.h
+++ b/drivers/media/usb/cpia2/cpia2.h
@@ -429,6 +429,7 @@ int cpia2_send_command(struct camera_data *cam, struct cpia2_command *cmd);
 int cpia2_do_command(struct camera_data *cam,
 		     unsigned int command,
 		     unsigned char direction, unsigned char param);
+void cpia2_deinit_camera_struct(struct camera_data *cam, struct usb_interface *intf);
 struct camera_data *cpia2_init_camera_struct(struct usb_interface *intf);
 int cpia2_init_camera(struct camera_data *cam);
 int cpia2_allocate_buffers(struct camera_data *cam);
diff --git a/drivers/media/usb/cpia2/cpia2_core.c b/drivers/media/usb/cpia2/cpia2_core.c
index e747548ab286..b5a2d06fb356 100644
--- a/drivers/media/usb/cpia2/cpia2_core.c
+++ b/drivers/media/usb/cpia2/cpia2_core.c
@@ -2163,6 +2163,18 @@ static void reset_camera_struct(struct camera_data *cam)
 	cam->height = cam->params.roi.height;
 }
 
+/******************************************************************************
+ *
+ *  cpia2_init_camera_struct
+ *
+ *  Deinitialize camera struct
+ *****************************************************************************/
+void cpia2_deinit_camera_struct(struct camera_data *cam, struct usb_interface *intf)
+{
+	v4l2_device_unregister(&cam->v4l2_dev);
+	kfree(cam);
+}
+
 /******************************************************************************
  *
  *  cpia2_init_camera_struct
diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c
index 3ab80a7b4498..76aac06f9fb8 100644
--- a/drivers/media/usb/cpia2/cpia2_usb.c
+++ b/drivers/media/usb/cpia2/cpia2_usb.c
@@ -844,15 +844,13 @@ static int cpia2_usb_probe(struct usb_interface *intf,
 	ret = set_alternate(cam, USBIF_CMDONLY);
 	if (ret < 0) {
 		ERR("%s: usb_set_interface error (ret = %d)\n", __func__, ret);
-		kfree(cam);
-		return ret;
+		goto alt_err;
 	}
 
 
 	if((ret = cpia2_init_camera(cam)) < 0) {
 		ERR("%s: failed to initialize cpia2 camera (ret = %d)\n", __func__, ret);
-		kfree(cam);
-		return ret;
+		goto alt_err;
 	}
 	LOG("  CPiA Version: %d.%02d (%d.%d)\n",
 	       cam->params.version.firmware_revision_hi,
@@ -872,11 +870,14 @@ static int cpia2_usb_probe(struct usb_interface *intf,
 	ret = cpia2_register_camera(cam);
 	if (ret < 0) {
 		ERR("%s: Failed to register cpia2 camera (ret = %d)\n", __func__, ret);
-		kfree(cam);
-		return ret;
+		goto alt_err;
 	}
 
 	return 0;
+
+alt_err:
+	cpia2_deinit_camera_struct(cam, intf);
+	return ret;
 }
 
 /******************************************************************************
-- 
2.31.1