memory leak in dvb_create_media_graph

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    407ab579 Merge tag 'for-linus' of git://git.kernel.org/pub..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1472cf3a500000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a3f13716fa0212fd
dashboard link: https://syzkaller.appspot.com/bug?extid=7f09440acc069a0d38ac
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1496773a500000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11f5d04e500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7f09440acc069a0d38ac@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: memory leak
unreferenced object 0xffff888109ceb880 (size 128):
  comm "kworker/0:4", pid 4908, jiffies 4294942256 (age 13.710s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 06 05 00 00 00 00 00 00  ................
    00 01 00 00 00 00 ad de 22 01 00 00 00 00 ad de  ........".......
  backtrace:
    [<0000000063129123>] kmalloc include/linux/slab.h:552 [inline]
    [<0000000063129123>] kzalloc include/linux/slab.h:664 [inline]
    [<0000000063129123>] dvb_create_media_graph+0x301/0x7d0 drivers/media/dvb-core/dvbdev.c:662
    [<00000000446ffd59>] dvb_usb_adapter_frontend_init+0x180/0x1b0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:327
    [<000000004de3ceb1>] dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:84 [inline]
    [<000000004de3ceb1>] dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:173 [inline]
    [<000000004de3ceb1>] dvb_usb_device_init.cold+0x4d0/0x6ae drivers/media/usb/dvb-usb/dvb-usb-init.c:287
    [<0000000044208faf>] gp8psk_usb_probe+0x2a/0x50 drivers/media/usb/dvb-usb/gp8psk.c:304
    [<000000001403cbb0>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
    [<000000009ed11d03>] really_probe+0x159/0x480 drivers/base/dd.c:554
    [<000000000cd27108>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
    [<000000005568f559>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844
    [<00000000f9838db7>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
    [<000000006449b02e>] __device_attach+0x122/0x250 drivers/base/dd.c:912
    [<000000007f8d4f6c>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
    [<0000000023ea078a>] device_add+0x5ac/0xc30 drivers/base/core.c:2936
    [<0000000024710aa6>] usb_set_configuration+0x9de/0xb90 drivers/usb/core/message.c:2159
    [<000000009af942e5>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238
    [<00000000a5638b3c>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293
    [<000000009ed11d03>] really_probe+0x159/0x480 drivers/base/dd.c:554

BUG: memory leak
unreferenced object 0xffff888110cbec80 (size 128):
  comm "kworker/1:2", pid 4591, jiffies 4294942850 (age 7.770s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 06 05 00 00 00 00 00 00  ................
    00 01 00 00 00 00 ad de 22 01 00 00 00 00 ad de  ........".......
  backtrace:
    [<0000000063129123>] kmalloc include/linux/slab.h:552 [inline]
    [<0000000063129123>] kzalloc include/linux/slab.h:664 [inline]
    [<0000000063129123>] dvb_create_media_graph+0x301/0x7d0 drivers/media/dvb-core/dvbdev.c:662
    [<00000000446ffd59>] dvb_usb_adapter_frontend_init+0x180/0x1b0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:327
    [<000000004de3ceb1>] dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:84 [inline]
    [<000000004de3ceb1>] dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:173 [inline]
    [<000000004de3ceb1>] dvb_usb_device_init.cold+0x4d0/0x6ae drivers/media/usb/dvb-usb/dvb-usb-init.c:287
    [<0000000044208faf>] gp8psk_usb_probe+0x2a/0x50 drivers/media/usb/dvb-usb/gp8psk.c:304
    [<000000001403cbb0>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
    [<000000009ed11d03>] really_probe+0x159/0x480 drivers/base/dd.c:554
    [<000000000cd27108>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
    [<000000005568f559>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844
    [<00000000f9838db7>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
    [<000000006449b02e>] __device_attach+0x122/0x250 drivers/base/dd.c:912
    [<000000007f8d4f6c>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
    [<0000000023ea078a>] device_add+0x5ac/0xc30 drivers/base/core.c:2936
    [<0000000024710aa6>] usb_set_configuration+0x9de/0xb90 drivers/usb/core/message.c:2159
    [<000000009af942e5>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238
    [<00000000a5638b3c>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293
    [<000000009ed11d03>] really_probe+0x159/0x480 drivers/base/dd.c:554



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