syzbot

loop0: detected capacity change from 0 to 64
Unable to handle kernel paging request at virtual address dfff800000000008
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff800000000008] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4492 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : hfs_find_init+0x6c/0x1c8 fs/hfs/bfind.c:21
lr : hfs_find_init+0x30/0x1c8 fs/hfs/bfind.c:16
sp : ffff8000211970b0
x29: ffff8000211970b0 x28: dfff800000000000 x27: 0000000000000000
x26: ffff0000e0b892b8 x25: 0000000000000008 x24: dfff800000000000
x23: 0000000000000000 x22: ffff800021197198 x21: 0000000000000040
x20: ffff800021197180 x19: 0000000000000000 x18: ffff800011b7bf60
x17: ffff800018338000 x16: ffff8000082d11b8 x15: ffff800017e19000
x14: 0000000000000007 x13: 1ffff00004232e30 x12: 0000000000ff0100
x11: ff00800008f9a944 x10: 0000000000000000 x9 : ffff800008f9a944
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff8000184e6150 x4 : 0000000000000000 x3 : 0000000000000030
x2 : 0000000000000008 x1 : ffff800021197180 x0 : ffff800021197190
Call trace:
 hfs_find_init+0x6c/0x1c8 fs/hfs/bfind.c:21
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_get_block+0x420/0xa3c fs/hfs/extent.c:366
 block_read_full_folio+0x2f4/0x980 fs/buffer.c:2271
 hfs_read_folio+0x28/0x38 fs/hfs/inode.c:39
 filemap_read_folio+0x134/0x384 mm/filemap.c:2490
 do_read_cache_folio+0x24c/0x538 mm/filemap.c:3659
 do_read_cache_page mm/filemap.c:3701 [inline]
 read_cache_page+0x6c/0x184 mm/filemap.c:3710
 read_mapping_page include/linux/pagemap.h:793 [inline]
 hfs_btree_open+0x404/0xfd0 fs/hfs/btree.c:78
 hfs_mdb_get+0xeb4/0x1a0c fs/hfs/mdb.c:199
 hfs_fill_super+0xc84/0x1238 fs/hfs/super.c:406
 mount_bdev+0x264/0x358 fs/super.c:1443
 hfs_mount+0x44/0x58 fs/hfs/super.c:458
 legacy_get_tree+0xd4/0x16c fs/fs_context.c:632
 vfs_get_tree+0x90/0x274 fs/super.c:1573
 do_new_mount+0x228/0x810 fs/namespace.c:3078
 path_mount+0x5bc/0xe80 fs/namespace.c:3408
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount fs/namespace.c:3606 [inline]
 __arm64_sys_mount+0x49c/0x59c fs/namespace.c:3606
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 97e52a9d 91010275 f90002df d343feb9 (38f86b28) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97e52a9d 	bl	0xffffffffff94aa74
   4:	91010275 	add	x21, x19, #0x40
   8:	f90002df 	str	xzr, [x22]
   c:	d343feb9 	lsr	x25, x21, #3
* 10:	38f86b28 	ldrsb	w8, [x25, x24] <-- trapping instruction