syzbot

workqueue: max_active 2097158 requested for btrfs-compressed-write is out of range, clamping between 1 and 512
BTRFS info (device loop0: state C): enabling ssd optimizations
BTRFS error (device loop0: state MC): unrecognized mount option 'L'
Unable to handle kernel paging request at virtual address dfff800000000003
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
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
[dfff800000000003] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4468 Comm: syz.0.16 Not tainted 6.1.144-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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+0x8d4/0x35a8 fs/btrfs/disk-io.c:4357
lr : lowmem_page_address include/linux/mm.h:1805 [inline]
lr : btrfs_header_level fs/btrfs/ctree.h:2375 [inline]
lr : backup_super_roots fs/btrfs/disk-io.c:2005 [inline]
lr : write_all_supers+0x82c/0x35a8 fs/btrfs/disk-io.c:4357
sp : ffff800020b872c0
x29: ffff800020b87620 x28: 1ffff00002959078 x27: 0000000000000009
x26: 0000000000000003 x25: ffff0000d29f4bc5 x24: ffff0000ca1a46c8
x23: ffff0000d29f4b2b x22: ffff800014ac8000 x21: dfff800000000000
x20: dfff800000000000 x19: 0000000000000018 x18: ffff800011aabce0
x17: ffff8000181e6000 x16: ffff8000082e8124 x15: ffff800017cc6fc0
x14: ffff0000cf782658 x13: 1ffff00002a160b1 x12: 0000000000ff0100
x11: ff00800009f33194 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : ffff800009f260c4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000082e8180
x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffff0000cc33ba50
Call trace:
 backup_super_roots fs/btrfs/disk-io.c:2007 [inline]
 write_all_supers+0x8d4/0x35a8 fs/btrfs/disk-io.c:4357
 btrfs_commit_transaction+0x19b4/0x29f0 fs/btrfs/transaction.c:2511
 btrfs_set_free_space_cache_v1_active+0x7c/0x258 fs/btrfs/free-space-cache.c:4134
 btrfs_remount_cleanup fs/btrfs/super.c:1992 [inline]
 btrfs_remount+0x5b8/0x1148 fs/btrfs/super.c:2182
 legacy_reconfigure+0xf8/0x110 fs/fs_context.c:655
 reconfigure_super+0x1d4/0x79c fs/super.c:977
 do_remount fs/namespace.c:2714 [inline]
 path_mount+0xbd4/0xe78 fs/namespace.c:3380
 do_mount fs/namespace.c:3401 [inline]
 __do_sys_mount fs/namespace.c:3609 [inline]
 __se_sys_mount fs/namespace.c:3586 [inline]
 __arm64_sys_mount+0x49c/0x584 fs/namespace.c:3586
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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: d2d00014 f2fbfff4 91006113 d343fe7a (38756b48) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	d2d00014 	mov	x20, #0x800000000000        	// #140737488355328
   4:	f2fbfff4 	movk	x20, #0xdfff, lsl #48
   8:	91006113 	add	x19, x8, #0x18
   c:	d343fe7a 	lsr	x26, x19, #3
* 10:	38756b48 	ldrb	w8, [x26, x21] <-- trapping instruction