loop3: detected capacity change from 0 to 128 EXT4-fs (loop3): mounted filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09 r/w without journal. Quota mode: none. ext4 filesystem being mounted at /32/mnt supports timestamps until 2038-01-19 (0x7fffffff) 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: 16707 Comm: syz.3.3041 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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 42 db f7 fe 49 8d 5d 18 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 48 26 4f ff 48 8b 1b 48 83 c3 30 RSP: 0018:ffffc900034d7800 EFLAGS: 00010206 RAX: 0000000000000003 RBX: 0000000000000018 RCX: 0000000000080000 RDX: ffffc9000c839000 RSI: 0000000000000417 RDI: 0000000000000418 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: ffffc900034d7998 R11: fffff5200069af36 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880787e0da8 R15: dffffc0000000000 FS: 00007fce8d1d66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fce821f7000 CR3: 000000007cf8a000 CR4: 00000000003506f0 DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081 DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: utf8byte+0x34f/0x1370 fs/unicode/utf8-norm.c:-1 utf8_casefold+0x130/0x230 fs/unicode/utf8-core.c:109 ext4_fname_setup_ci_filename+0x1d5/0x430 fs/ext4/namei.c:1463 ext4_fname_prepare_lookup+0x213/0x3a0 fs/ext4/crypto.c:55 ext4_lookup_entry fs/ext4/namei.c:1767 [inline] ext4_lookup+0xfa/0x6d0 fs/ext4/namei.c:1842 lookup_one_qstr_excl+0x112/0x250 fs/namei.c:1609 filename_create+0x222/0x460 fs/namei.c:3883 do_mkdirat+0xa1/0x440 fs/namei.c:4128 __do_sys_mkdirat fs/namei.c:4151 [inline] __se_sys_mkdirat fs/namei.c:4149 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fce8c38eec9 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:00007fce8d1d6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fce8c5e5fa0 RCX: 00007fce8c38eec9 RDX: 0000000000000100 RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007fce8c411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fce8c5e6038 R14: 00007fce8c5e5fa0 R15: 00007ffe953ef828 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 42 db f7 fe 49 8d 5d 18 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 48 26 4f ff 48 8b 1b 48 83 c3 30 RSP: 0018:ffffc900034d7800 EFLAGS: 00010206 RAX: 0000000000000003 RBX: 0000000000000018 RCX: 0000000000080000 RDX: ffffc9000c839000 RSI: 0000000000000417 RDI: 0000000000000418 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: ffffc900034d7998 R11: fffff5200069af36 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880787e0da8 R15: dffffc0000000000 FS: 00007fce8d1d66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc2d878fdc CR3: 000000007cf8a000 CR4: 00000000003506f0 DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081 DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400 ---------------- 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 42 db f7 fe call 0xfef7db61 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 48 26 4f ff call 0xff4f2681 39: 48 8b 1b mov (%rbx),%rbx 3c: 48 83 c3 30 add $0x30,%rbx