Re: [syzbot] [mm?] general protection fault in find_lock_task_mm

[syzbot <syzbot+c2e074db555379260750@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in tomoyo_init_request_info

Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]
CPU: 0 UID: 0 PID: 12774 Comm: syz.0.2725 Not tainted 6.13.0-rc3-syzkaller-gf44d154d6e3d-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
RIP: 0010:tomoyo_init_request_info+0x6f/0x370 security/tomoyo/util.c:1028
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 98 02 00 00 48 8d 7d 50 48 89 6b 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 5d 02 00 00 48 8d 7b 4b 44 0f b6 6d
RSP: 0018:ffffc9000d0af790 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffffc9000d0af808 RCX: 0000000000000000
RDX: 000000000000000a RSI: ffffffff8452d8b7 RDI: 0000000000000050
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000d0af808 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000109002 R14: ffff88802d9bae80 R15: 0000000000000006
FS:  00007fb5170df6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb5170def98 CR3: 000000001ff52000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tomoyo_check_open_permission+0x27a/0x3c0 security/tomoyo/file.c:769
 tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
 security_file_open+0x84/0x1e0 security/security.c:3105
 do_dentry_open+0x57e/0x1ea0 fs/open.c:928
 vfs_open+0x82/0x3f0 fs/open.c:1075
 do_open fs/namei.c:3828 [inline]
 path_openat+0x1e6a/0x2d60 fs/namei.c:3987
 do_filp_open+0x20c/0x470 fs/namei.c:4014
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1428
 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: 0033:0x7fb516385d19
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:00007fb5170df038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb516575fa0 RCX: 00007fb516385d19
RDX: 0000000000189002 RSI: 0000000020000100 RDI: ffffffffffffff9c
RBP: 00007fb516401a20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fb516575fa0 R15: 00007fff07409218
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:tomoyo_init_request_info+0x6f/0x370 security/tomoyo/util.c:1028
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 98 02 00 00 48 8d 7d 50 48 89 6b 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 5d 02 00 00 48 8d 7b 4b 44 0f b6 6d
RSP: 0018:ffffc9000d0af790 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffffc9000d0af808 RCX: 0000000000000000
RDX: 000000000000000a RSI: ffffffff8452d8b7 RDI: 0000000000000050
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000d0af808 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000109002 R14: ffff88802d9bae80 R15: 0000000000000006
FS:  00007fb5170df6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b7f5b65950 CR3: 000000001ff52000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	0f 85 98 02 00 00    	jne    0x2a9
  11:	48 8d 7d 50          	lea    0x50(%rbp),%rdi
  15:	48 89 6b 10          	mov    %rbp,0x10(%rbx)
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	74 06                	je     0x38
  32:	0f 8e 5d 02 00 00    	jle    0x295
  38:	48 8d 7b 4b          	lea    0x4b(%rbx),%rdi
  3c:	44                   	rex.R
  3d:	0f                   	.byte 0xf
  3e:	b6 6d                	mov    $0x6d,%dh


Tested on:

commit:         f44d154d Merge tag 'soc-fixes-6.13' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=126274f8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c22efbd20f8da769
dashboard link: https://syzkaller.appspot.com/bug?extid=c2e074db555379260750
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15d9560f980000