KMSAN: uninit-value in tomoyo_check_inet_address

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    3b955a40 usb-fuzzer: main usb gadget fuzzer driver
git tree:       kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=1027e608a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=602468164ccdc30a
dashboard link: https://syzkaller.appspot.com/bug?extid=1018d578c410f9f37261
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
06d00afa61eef8f7f501ebdb4e8612ea43ec2d78)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+1018d578c410f9f37261 at syzkaller.appspotmail.com

==================================================================
BUG: KMSAN: uninit-value in tomoyo_check_inet_address+0x143/0xd10  
security/tomoyo/network.c:508
CPU: 0 PID: 22966 Comm: syz-executor.2 Not tainted 5.1.0+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x191/0x1f0 lib/dump_stack.c:113
  kmsan_report+0x130/0x2a0 mm/kmsan/kmsan.c:619
  __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
  tomoyo_check_inet_address+0x143/0xd10 security/tomoyo/network.c:508
  tomoyo_socket_bind_permission+0x343/0x3b0 security/tomoyo/network.c:741
  tomoyo_socket_bind+0x8b/0xa0 security/tomoyo/tomoyo.c:471
  security_socket_bind+0x127/0x200 security/security.c:1943
  __sys_bind+0x536/0x7c0 net/socket.c:1623
  __do_sys_bind net/socket.c:1638 [inline]
  __se_sys_bind+0x8d/0xb0 net/socket.c:1636
  __x64_sys_bind+0x4a/0x70 net/socket.c:1636
  do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
  entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x458da9
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4aeb5bbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4aeb5bc6d4
R13: 00000000004bee1f R14: 00000000004cfe68 R15: 00000000ffffffff

Local variable description: ----address at __sys_bind
Variable was created at:
  sockfd_lookup_light net/socket.c:488 [inline]
  __sys_bind+0x8c/0x7c0 net/socket.c:1619
  __do_sys_bind net/socket.c:1638 [inline]
  __se_sys_bind+0x8d/0xb0 net/socket.c:1636
==================================================================


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