[BUG] media: ttusb-dec: kmemleak reports dvb_frontend_private leak after frontend registration failure

[Shuangpeng]

Hi Kernel Maintainers,

I hit the following kmemleak report while testing current upstream kernel:

kmemleak: unreferenced object in dvb_register_frontend

on commit: e8c2f9fdadee7cbc75134dc463c1e0d856d6e5c7 (May 25 2026)

The reproducer and .config files are here.
https://gist.github.com/shuangpengbai/e8dd4867a7b7907c1857ca732e7d56e5

I’m happy to test debug patches or provide additional information.

Reported-by: Shuangpeng Bai <shuangpeng.kernel@xxxxxxxxx>

unreferenced object 0xffff88816510b000 (size 1024):
comm "kworker/0:0", pid 9129, jiffies 4295084343
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
backtrace (crc 2b918277):
__kmalloc_cache_noprof (./include/linux/kmemleak.h:44 mm/slub.c:4575 mm/slub.c:4899 mm/slub.c:5415)
dvb_register_frontend (./include/linux/slab.h:950 ./include/linux/slab.h:1188 drivers/media/dvb-core/dvb_frontend.c:3024)
ttusb_dec_probe (drivers/media/usb/ttusb-dec/ttusb_dec.c:1695)
usb_probe_interface (drivers/usb/core/driver.c:396)
really_probe (drivers/base/dd.c:? drivers/base/dd.c:709)
__driver_probe_device (drivers/base/dd.c:871)
driver_probe_device (drivers/base/dd.c:901)
__device_attach_driver (drivers/base/dd.c:1029)
bus_for_each_drv (drivers/base/bus.c:500)
__device_attach (drivers/base/dd.c:1101)
device_initial_probe (drivers/base/dd.c:1156)
bus_probe_device (drivers/base/bus.c:613)
device_add (drivers/base/core.c:3706)
usb_set_configuration (drivers/usb/core/message.c:2268)
usb_generic_driver_probe (drivers/usb/core/generic.c:250)
usb_probe_device (drivers/usb/core/driver.c:291)


Best,
Shuangpeng