[PATCH] dvb: usb: fix use after free in dvb_usb_device_exit

[Oliver Neukum]

dvb_usb_device_exit() frees and uses teh device name in that order
Fix by storing the name in a buffer before freeing it

Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Reported-by: syzbot+26ec41e9f788b3eba396@xxxxxxxxxxxxxxxxxxxxxxxxx
---
 drivers/media/usb/dvb-usb/dvb-usb-init.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
index 99951e02a880..2e1670cc3903 100644
--- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
@@ -288,13 +288,18 @@ void dvb_usb_device_exit(struct usb_interface *intf)
 {
 	struct dvb_usb_device *d = usb_get_intfdata(intf);
 	const char *name = "generic DVB-USB module";
+	char identifier[40];
 
 	usb_set_intfdata(intf, NULL);
 	if (d != NULL && d->desc != NULL) {
 		name = d->desc->name;
+		memcpy(identifier, name, 39);
+		identifier[39] = NULL;
 		dvb_usb_exit(d);
+	} else {
+		memcpy(identifier, name, 39);
 	}
-	info("%s successfully deinitialized and disconnected.", name);
+	info("%s successfully deinitialized and disconnected.", identifier);
 
 }
 EXPORT_SYMBOL(dvb_usb_device_exit);
-- 
2.16.4