[selinux?] general protection fault in selinux_socket_unix_may_send

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4bdec23f971b Merge tag 'hwmon-for-v6.3-rc4' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13b12e1ec80000
kernel config: https://syzkaller.appspot.com/x/.config?x=8ef27c4ff127cda5
dashboard link: https://syzkaller.appspot.com/bug?extid=8a837fa30ef7cc2d748e
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [b...@vger.kernel.org epa...@parisplace.org gpic...@igalia.com kees...@chromium.org linux-h...@vger.kernel.org linux-...@vger.kernel.org pa...@paul-moore.com sel...@vger.kernel.org stephen.sm...@gmail.com tony...@intel.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/627886b3cd3c/disk-4bdec23f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ba6647177a26/vmlinux-4bdec23f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fda6b8462273/bzImage-4bdec23f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8a837f...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0060000070: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x0000000300000380-0x0000000300000387]
CPU: 0 PID: 4422 Comm: klogd Not tainted 6.3.0-rc3-syzkaller-00322-g4bdec23f971b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
RIP: 0010:selinux_socket_unix_may_send+0x101/0x270 security/selinux/hooks.c:4998
Code: c1 ea 03 80 3c 02 00 0f 85 61 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 65 18 49 8d bc 24 80 04 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 30 01 00 00 49 8b ac 24 80 04 00 00 31 c0 b9 07
RSP: 0018:ffffc900030cfa38 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff92000619f48 RCX: 0000000000000000
RDX: 0000000060000070 RSI: ffffffff83c9980e RDI: 0000000300000380
RBP: ffff88805a20d040 R08: 0000000000000003 R09: 0000000000000005
R10: 0000000000000002 R11: 0000000000000000 R12: 00000002ffffff00
R13: ffff88807f7ee4c0 R14: ffff88802756d700 R15: 0000000000000002
FS: 00007f995b784800(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faa1c8e6fc0 CR3: 000000007e6ec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
security_unix_may_send+0x4c/0xa0 security/security.c:2262
unix_dgram_sendmsg+0xbc0/0x1950 net/unix/af_unix.c:2035
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg+0xde/0x190 net/socket.c:747
__sys_sendto+0x23a/0x340 net/socket.c:2142
__do_sys_sendto net/socket.c:2154 [inline]
__se_sys_sendto net/socket.c:2150 [inline]
__x64_sys_sendto+0xe1/0x1b0 net/socket.c:2150
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f995b9200ac
Code: 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 19 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 64 c3 0f 1f 00 55 48 83 ec 20 48 89 54 24 10
RSP: 002b:00007ffe8c94c498 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f995b9200ac
RDX: 00000000000000a0 RSI: 0000555ef28a3140 RDI: 0000000000000003
RBP: 0000555ef28972c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000014
R13: 0000000000000001 R14: 00007f995ba9b77d R15: 00007ffe8c94c5a8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:selinux_socket_unix_may_send+0x101/0x270 security/selinux/hooks.c:4998
Code: c1 ea 03 80 3c 02 00 0f 85 61 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 65 18 49 8d bc 24 80 04 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 30 01 00 00 49 8b ac 24 80 04 00 00 31 c0 b9 07
RSP: 0018:ffffc900030cfa38 EFLAGS: 00010202

RAX: dffffc0000000000 RBX: 1ffff92000619f48 RCX: 0000000000000000
RDX: 0000000060000070 RSI: ffffffff83c9980e RDI: 0000000300000380
RBP: ffff88805a20d040 R08: 0000000000000003 R09: 0000000000000005
R10: 0000000000000002 R11: 0000000000000000 R12: 00000002ffffff00
R13: ffff88807f7ee4c0 R14: ffff88802756d700 R15: 0000000000000002
FS: 00007f995b784800(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faa1c8e6fc0 CR3: 000000007e6ec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: c1 ea 03 shr $0x3,%edx
3: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
7: 0f 85 61 01 00 00 jne 0x16e
d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
14: fc ff df
17: 4c 8b 65 18 mov 0x18(%rbp),%r12
1b: 49 8d bc 24 80 04 00 lea 0x480(%r12),%rdi
22: 00
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 30 01 00 00 jne 0x164
34: 49 8b ac 24 80 04 00 mov 0x480(%r12),%rbp
3b: 00
3c: 31 c0 xor %eax,%eax
3e: b9 .byte 0xb9
3f: 07 (bad)


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.