syzbot

EXT4-fs (loop0): encrypted files will use data=ordered instead of data journaling mode
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
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: 5933 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:utf8nlookup+0x39/0xa50 fs/unicode/utf8-norm.c:306
Code: 89 44 24 10 49 89 ce 48 89 14 24 89 f5 49 89 fd 49 bf 00 00 00 00 00 fc ff df e8 c2 56 f4 fe 49 8d 5d 18 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 d8 8d 4c ff 48 8b 1b 48 83 c3 30
RSP: 0018:ffffc90003267800 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888076bc0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 000000000000004c R09: 0000000000000000
R10: ffffc90003267998 R11: fffff5200064cf36 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888022bd1b10 R15: dffffc0000000000
FS:  000055557b7f5500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001b80 CR3: 0000000026fbd000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 utf8byte+0x34f/0x1370 fs/unicode/utf8-norm.c:-1
 utf8_casefold+0x146/0x260 fs/unicode/utf8-core.c:109
 ext4_fname_setup_ci_filename+0x1d5/0x430 fs/ext4/namei.c:1463
 ext4_fname_prepare_lookup+0x230/0x3d0 fs/ext4/crypto.c:55
 ext4_lookup_entry fs/ext4/namei.c:1767 [inline]
 ext4_lookup+0x125/0x710 fs/ext4/namei.c:1842
 lookup_one_qstr_excl+0x112/0x250 fs/namei.c:1617
 filename_create+0x23e/0x480 fs/namei.c:3891
 do_mkdirat+0xa9/0x450 fs/namei.c:4136
 __do_sys_mkdirat fs/namei.c:4159 [inline]
 __se_sys_mkdirat fs/namei.c:4157 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4157
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9a01f9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc76671e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f9a02215fa0 RCX: 00007f9a01f9cdd9
RDX: 0000000000000000 RSI: 0000200000000340 RDI: 0000000000000006
RBP: 00007f9a02032d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9a02215fac R14: 00007f9a02215fa0 R15: 00007f9a02215fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:utf8nlookup+0x39/0xa50 fs/unicode/utf8-norm.c:306
Code: 89 44 24 10 49 89 ce 48 89 14 24 89 f5 49 89 fd 49 bf 00 00 00 00 00 fc ff df e8 c2 56 f4 fe 49 8d 5d 18 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 d8 8d 4c ff 48 8b 1b 48 83 c3 30
RSP: 0018:ffffc90003267800 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888076bc0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 000000000000004c R09: 0000000000000000
R10: ffffc90003267998 R11: fffff5200064cf36 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888022bd1b10 R15: dffffc0000000000
FS:  000055557b7f5500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001b80 CR3: 0000000026fbd000 CR4: 00000000003506f0
----------------
Code disassembly (best guess):
   0:	89 44 24 10          	mov    %eax,0x10(%rsp)
   4:	49 89 ce             	mov    %rcx,%r14
   7:	48 89 14 24          	mov    %rdx,(%rsp)
   b:	89 f5                	mov    %esi,%ebp
   d:	49 89 fd             	mov    %rdi,%r13
  10:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  17:	fc ff df
  1a:	e8 c2 56 f4 fe       	call   0xfef456e1
  1f:	49 8d 5d 18          	lea    0x18(%r13),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 d8 8d 4c ff       	call   0xff4c8e11
  39:	48 8b 1b             	mov    (%rbx),%rbx
  3c:	48 83 c3 30          	add    $0x30,%rbx