[syzbot] [tomoyo?] general protection fault in tomoyo_flush

[syzbot <syzbot+9ad93776d062020fdeae@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    0bc21e701a6f MAINTAINERS: Remove Olof from SoC maintainers
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17c198b0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=86dd15278dbfe19f
dashboard link: https://syzkaller.appspot.com/bug?extid=9ad93776d062020fdeae
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0ddf8c394b52/disk-0bc21e70.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e1f9219449bc/vmlinux-0bc21e70.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bd6fd63b12da/bzImage-0bc21e70.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9ad93776d062020fdeae@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 27185 Comm: syz.2.4308 Not tainted 6.13.0-rc5-syzkaller-00012-g0bc21e701a6f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:strlen+0x1e/0xa0 lib/string.c:413
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 89 fd 48 c1 ea 03 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 50 80 7d 00 00
RSP: 0018:ffffc9000d6679f0 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: ffffffff845000d4
RDX: 0000000000000000 RSI: ffffffff84500115 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000003 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff1100867ae16 R15: 0000000000000002
FS:  00007fa57d3f66c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000007000 CR3: 000000003289e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tomoyo_flush+0xb1/0x4b0 security/tomoyo/common.c:209
 tomoyo_set_string+0xaf/0xe0 security/tomoyo/common.c:255
 tomoyo_print_condition security/tomoyo/common.c:1292 [inline]
 tomoyo_print_entry+0xef8/0x2720 security/tomoyo/common.c:1570
 tomoyo_read_domain2+0xa3/0x380 security/tomoyo/common.c:1596
 tomoyo_read_domain security/tomoyo/common.c:1649 [inline]
 tomoyo_read_domain+0x3d2/0x9c0 security/tomoyo/common.c:1610
 tomoyo_read_control+0x281/0x510 security/tomoyo/common.c:2591
 vfs_read+0x1df/0xbe0 fs/read_write.c:563
 ksys_read+0x12b/0x250 fs/read_write.c:708
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa57f585d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa57d3f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fa57f775fa0 RCX: 00007fa57f585d29
RDX: 000000000000b4d3 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fa57f601b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa57f775fa0 R15: 00007ffdc9ebbd58
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:strlen+0x1e/0xa0 lib/string.c:413
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 89 fd 48 c1 ea 03 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 50 80 7d 00 00
RSP: 0018:ffffc9000d6679f0 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: ffffffff845000d4
RDX: 0000000000000000 RSI: ffffffff84500115 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000003 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff1100867ae16 R15: 0000000000000002
FS:  00007fa57d3f66c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c824cf7 CR3: 000000003289e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	f3 0f 1e fa          	endbr64
  10:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  17:	fc ff df
  1a:	48 89 fa             	mov    %rdi,%rdx
  1d:	55                   	push   %rbp
  1e:	48 89 fd             	mov    %rdi,%rbp
  21:	48 c1 ea 03          	shr    $0x3,%rdx
  25:	53                   	push   %rbx
  26:	48 83 ec 08          	sub    $0x8,%rsp
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	48 89 fa             	mov    %rdi,%rdx
  31:	83 e2 07             	and    $0x7,%edx
  34:	38 d0                	cmp    %dl,%al
  36:	7f 04                	jg     0x3c
  38:	84 c0                	test   %al,%al
  3a:	75 50                	jne    0x8c
  3c:	80 7d 00 00          	cmpb   $0x0,0x0(%rbp)


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