media: dvb: usb: fix use after free in dvb_usb_device_exit

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

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-by: syzbot+26ec41e9f788b3eba396@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
index 99951e02a8801835fe83d74e6275be756deb0f38..dd063a736df5d1c2b54e0520976542655e856239 100644 (file)
--- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
@@ -287,12 +287,15 @@ EXPORT_SYMBOL(dvb_usb_device_init);
 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";
+       const char *default_name = "generic DVB-USB module";
+       char name[40];
 
        usb_set_intfdata(intf, NULL);
        if (d != NULL && d->desc != NULL) {
-               name = d->desc->name;
+               strscpy(name, d->desc->name, sizeof(name));
                dvb_usb_exit(d);
+       } else {
+               strscpy(name, default_name, sizeof(name));
        }
        info("%s successfully deinitialized and disconnected.", name);