loop4: detected capacity change from 0 to 64
general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 0 PID: 16340 Comm: syz.4.2945 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:hfs_find_init+0x66/0x1d0 fs/hfs/bfind.c:21
Code: 7e 18 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 5c 5f 8a ff 49 c7 07 00 00 00 00 48 8d 6b 40 49 89 ef 49 c1 ef 03 <43> 0f b6 04 2f 84 c0 0f 85 01 01 00 00 8b 45 00 8d 7c 00 04 be c0
RSP: 0018:ffffc9000df5f3a8 EFLAGS: 00010202
RAX: 1ffff92001bebe93 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000e6fa000 RSI: 0000000000003c2f RDI: ffffc9000df5f490
RBP: 0000000000000040 R08: dffffc0000000000 R09: ffffc9000df5f480
R10: fffff52001bebe97 R11: 1ffff92001bebe90 R12: ffff88807c9e2678
R13: dffffc0000000000 R14: ffffc9000df5f480 R15: 0000000000000008
FS:  00007f4e6b6d66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000002cb93000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_get_block+0x518/0xbd0 fs/hfs/extent.c:366
 block_read_full_folio+0x3c9/0xed0 fs/buffer.c:2271
 filemap_read_folio+0x160/0x760 mm/filemap.c:2490
 do_read_cache_folio+0x2a0/0x760 mm/filemap.c:3627
 do_read_cache_page+0x32/0x220 mm/filemap.c:3669
 read_mapping_page include/linux/pagemap.h:791 [inline]
 hfs_btree_open+0x568/0x10b0 fs/hfs/btree.c:78
 hfs_mdb_get+0x12db/0x2010 fs/hfs/mdb.c:199
 hfs_fill_super+0xe0b/0x1410 fs/hfs/super.c:406
 mount_bdev+0x287/0x3c0 fs/super.c:1443
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x24a/0xa40 fs/namespace.c:3063
 do_mount fs/namespace.c:3406 [inline]
 __do_sys_mount fs/namespace.c:3614 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3591
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4e6a79030a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f4e6b6d5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f4e6b6d5ef0 RCX: 00007f4e6a79030a
RDX: 0000200000000180 RSI: 0000200000000100 RDI: 00007f4e6b6d5eb0
RBP: 0000200000000180 R08: 00007f4e6b6d5ef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000100
R13: 00007f4e6b6d5eb0 R14: 00000000000002d9 R15: 0000200000000240
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hfs_find_init+0x66/0x1d0 fs/hfs/bfind.c:21
Code: 7e 18 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 5c 5f 8a ff 49 c7 07 00 00 00 00 48 8d 6b 40 49 89 ef 49 c1 ef 03 <43> 0f b6 04 2f 84 c0 0f 85 01 01 00 00 8b 45 00 8d 7c 00 04 be c0
RSP: 0018:ffffc9000df5f3a8 EFLAGS: 00010202

RAX: 1ffff92001bebe93 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000e6fa000 RSI: 0000000000003c2f RDI: ffffc9000df5f490
RBP: 0000000000000040 R08: dffffc0000000000 R09: ffffc9000df5f480
R10: fffff52001bebe97 R11: 1ffff92001bebe90 R12: ffff88807c9e2678
R13: dffffc0000000000 R14: ffffc9000df5f480 R15: 0000000000000008
FS:  00007f4e6b6d66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000002cb93000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	7e 18                	jle    0x1a
   2:	4c 89 f8             	mov    %r15,%rax
   5:	48 c1 e8 03          	shr    $0x3,%rax
   9:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
   e:	74 08                	je     0x18
  10:	4c 89 ff             	mov    %r15,%rdi
  13:	e8 5c 5f 8a ff       	call   0xff8a5f74
  18:	49 c7 07 00 00 00 00 	movq   $0x0,(%r15)
  1f:	48 8d 6b 40          	lea    0x40(%rbx),%rbp
  23:	49 89 ef             	mov    %rbp,%r15
  26:	49 c1 ef 03          	shr    $0x3,%r15
* 2a:	43 0f b6 04 2f       	movzbl (%r15,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 01 01 00 00    	jne    0x138
  37:	8b 45 00             	mov    0x0(%rbp),%eax
  3a:	8d 7c 00 04          	lea    0x4(%rax,%rax,1),%edi
  3e:	be                   	.byte 0xbe
  3f:	c0                   	.byte 0xc0