general protection fault in tomoyo_socket_sendmsg_permission

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    9dbc1c03 Merge tag 'xfs-5.10-fixes-3' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10453034500000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1735b7978b1c3721
dashboard link: https://syzkaller.appspot.com/bug?extid=95ce4b142579611ef0a9
compiler:       gcc (GCC) 10.1.0-syz 20200507
userspace arch: i386

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+95ce4b142579611ef0a9 at syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 PID: 23364 Comm: vhci_tx Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tomoyo_socket_sendmsg_permission+0x80/0x340 security/tomoyo/network.c:762
Code: c7 40 0c f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 a0 00 00 00 31 c0 e8 0b 70 f1 fd 48 8d 7d 18 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 7d 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c
RSP: 0018:ffffc90016f77ad0 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 1ffff92002deef5b RCX: ffffffff83b3789e
RDX: ffff8880186c8000 RSI: ffffffff837e9945 RDI: 0000000000000018
RBP: 0000000000000000 R08: 0000000000000030 R09: ffffc90016f77d97
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc90016f77ce8 R14: ffffc90016f77ce8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562623b70868 CR3: 000000002af19000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 security_socket_sendmsg+0x50/0xb0 security/security.c:2140
 sock_sendmsg+0x3f/0x120 net/socket.c:668
 vhci_send_cmd_submit+0x897/0xf90 drivers/usb/usbip/vhci_tx.c:139
 vhci_tx_loop+0xfc/0x370 drivers/usb/usbip/vhci_tx.c:241
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Modules linked in:
---[ end trace 535369ec3e6ef304 ]---
RIP: 0010:tomoyo_socket_sendmsg_permission+0x80/0x340 security/tomoyo/network.c:762
Code: c7 40 0c f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 a0 00 00 00 31 c0 e8 0b 70 f1 fd 48 8d 7d 18 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 7d 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c
RSP: 0018:ffffc90016f77ad0 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 1ffff92002deef5b RCX: ffffffff83b3789e
RDX: ffff8880186c8000 RSI: ffffffff837e9945 RDI: 0000000000000018
RBP: 0000000000000000 R08: 0000000000000030 R09: ffffc90016f77d97
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc90016f77ce8 R14: ffffc90016f77ce8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c3a930740 CR3: 000000002af19000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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