WARNING in media_create_pad_link

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    059e7e0f usb: raw-gadget: fix typo in uapi headers
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=10e77dfa100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b484a6e53b2b06ad
dashboard link: https://syzkaller.appspot.com/bug?extid=dd320d114deb3f5bb79b
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16cd44ac100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17b12b92100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+dd320d114deb3f5bb79b@xxxxxxxxxxxxxxxxxxxxxxxxx

uvcvideo 1-1:0.0: Entity type for entity Processing 1 was not initialized!
uvcvideo 1-1:0.0: Entity type for entity Input 255 was not initialized!
------------[ cut here ]------------
WARNING: CPU: 0 PID: 163 at drivers/media/mc/mc-entity.c:669 media_create_pad_link+0x500/0x650 drivers/media/mc/mc-entity.c:669
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 163 Comm: kworker/0:3 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xef/0x16e lib/dump_stack.c:118
 panic+0x2aa/0x6e1 kernel/panic.c:221
 __warn.cold+0x2f/0x30 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 fixup_bug arch/x86/kernel/traps.c:170 [inline]
 do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:media_create_pad_link+0x500/0x650 drivers/media/mc/mc-entity.c:669
Code: bc ea ff ff ff eb da e8 ee e0 37 fd 0f 0b 41 bc ea ff ff ff eb cb e8 df e0 37 fd 0f 0b 41 bc ea ff ff ff eb bc e8 d0 e0 37 fd <0f> 0b 41 bc ea ff ff ff eb ad e8 c1 e0 37 fd 0f 0b 41 bc ea ff ff
RSP: 0018:ffff8881ce48ef70 EFLAGS: 00010293
RAX: ff


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches