syzbot

BTRFS info (device loop0): max_inline at 4096
BTRFS info (device loop0): disk space caching is enabled
BTRFS info (device loop0): has skinny extents
BTRFS error (device loop0): nologreplay must be used with ro mount option
Unable to handle kernel paging request at virtual address dfff800000000000
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
[dfff800000000000] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4018 Comm: syz-executor243 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : backup_super_roots fs/btrfs/disk-io.c:2007 [inline]
pc : write_all_supers+0xee0/0x3a6c fs/btrfs/disk-io.c:4154
lr : lowmem_page_address include/linux/mm.h:1612 [inline]
lr : btrfs_header_level fs/btrfs/ctree.h:2194 [inline]
lr : backup_super_roots fs/btrfs/disk-io.c:2005 [inline]
lr : write_all_supers+0xdf4/0x3a6c fs/btrfs/disk-io.c:4154
sp : ffff80001d197200
x29: ffff80001d1975c0 x28: 1ffff000028a79eb x27: 0000000000000009
x26: ffff0000c9064b2b x25: dfff800000000000 x24: 0000000000000000
x23: 0000000000000000 x22: dfff800000000000 x21: 1fffe00019048008
x20: 0000000000000000 x19: ffff0000c8240040 x18: ffff80001d1972a0
x17: 0000000000000000 x16: ffff80000824ec08 x15: 000000000000c69d
x14: 000000000eef1ac6 x13: 0000000000000000 x12: 0000000000000003
x11: 0000000000000000 x10: 1fffe0001b4f62e8 x9 : ffff0000c8240000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : ffffffffffffffd0 x3 : 0000000000000010
x2 : 0000000000000003 x1 : 0000000000000000 x0 : ffff0000da7b1860
Call trace:
 backup_super_roots fs/btrfs/disk-io.c:2007 [inline]
 write_all_supers+0xee0/0x3a6c fs/btrfs/disk-io.c:4154
 btrfs_commit_transaction+0x1694/0x30f0 fs/btrfs/transaction.c:2462
 btrfs_set_free_space_cache_v1_active+0x78/0x280 fs/btrfs/free-space-cache.c:4001
 btrfs_remount_cleanup fs/btrfs/super.c:1914 [inline]
 btrfs_remount+0x644/0x130c fs/btrfs/super.c:2117
 legacy_reconfigure+0xfc/0x114 fs/fs_context.c:634
 reconfigure_super+0x1d0/0x6ec fs/super.c:938
 do_remount fs/namespace.c:2668 [inline]
 path_mount+0xbec/0x101c fs/namespace.c:3334
 do_mount fs/namespace.c:3355 [inline]
 __do_sys_mount fs/namespace.c:3563 [inline]
 __se_sys_mount fs/namespace.c:3540 [inline]
 __arm64_sys_mount+0x510/0x5e0 fs/namespace.c:3540
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: aa1303e0 97a09d0b f9400274 d343fe88 (38796908) 
---[ end trace e29f29eecefa5d3f ]---
----------------
Code disassembly (best guess):
   0:	aa1303e0 	mov	x0, x19
   4:	97a09d0b 	bl	0xfffffffffe827430
   8:	f9400274 	ldr	x20, [x19]
   c:	d343fe88 	lsr	x8, x20, #3
* 10:	38796908 	ldrb	w8, [x8, x25] <-- trapping instruction