syzbot

Unable to handle kernel paging request at virtual address dfff8000000000bd
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
[dfff8000000000bd] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4024 Comm: syz-executor292 Not tainted 5.15.185-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 : bio_associate_blkg_from_css+0xf8/0x858 block/blk-cgroup.c:1878
lr : bio_associate_blkg_from_css+0xd0/0x858 block/blk-cgroup.c:1875
sp : ffff80001f5c74f0
x29: ffff80001f5c7530 x28: ffff80001af60b90 x27: dfff800000000000
x26: ffff80001af60a80 x25: ffff0000c815d9c8 x24: dfff800000000000
x23: 1fffe0001902bb39 x22: ffff0000c815d980 x21: 00000000000005e8
x20: ffff0000c815d988 x19: 1fffe0001902bb31 x18: 0000000000000000
x17: ffff800016cf0000 x16: ffff8000082bdf08 x15: ffff8000089787ec
x14: ffff8000088f2488 x13: 1ffff0000282c06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000000 x9 : ffff80000a64685c
x8 : 00000000000000bd x7 : ffff80000a647730 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : ffff80001af60a80 x0 : ffff0000c815d980
Call trace:
 bio_associate_blkg_from_css+0xf8/0x858 block/blk-cgroup.c:1878
 bio_associate_blkg+0x24c/0x374 block/blk-cgroup.c:1904
 lbmStartIO+0x1b0/0x434 fs/jfs/jfs_logmgr.c:2130
 lbmWrite+0x2f4/0x3f0 fs/jfs/jfs_logmgr.c:2079
 lmNextPage+0x2f0/0x8b8 fs/jfs/jfs_logmgr.c:624
 lmWriteRecord+0xc54/0x15c8 fs/jfs/jfs_logmgr.c:537
 lmLogSync+0x3b0/0x88c fs/jfs/jfs_logmgr.c:977
 jfs_syncpt+0x70/0x94 fs/jfs/jfs_logmgr.c:1049
 jfs_sync_fs+0x8c/0xac fs/jfs/super.c:690
 sync_filesystem+0xe8/0x218 fs/sync.c:56
 generic_shutdown_super+0x70/0x2f0 fs/super.c:448
 kill_block_super+0x70/0xdc fs/super.c:1427
 deactivate_locked_super+0xb8/0x13c fs/super.c:335
 deactivate_super+0xf8/0x118 fs/super.c:366
 cleanup_mnt+0x3a4/0x458 fs/namespace.c:1139
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1146
 task_work_run+0x12c/0x1e0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 do_notify_resume+0x24b4/0x3128 arch/arm64/kernel/signal.c:949
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
 el0_svc+0xf0/0x1e0 arch/arm64/kernel/entry-common.c:609
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: 9788171f f9400288 9117a115 d343fea8 (387b6908) 
---[ end trace bdddd8a2c8d3b1e7 ]---
----------------
Code disassembly (best guess):
   0:	9788171f 	bl	0xfffffffffe205c7c
   4:	f9400288 	ldr	x8, [x20]
   8:	9117a115 	add	x21, x8, #0x5e8
   c:	d343fea8 	lsr	x8, x21, #3
* 10:	387b6908 	ldrb	w8, [x8, x27] <-- trapping instruction