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: 4019 Comm: syz-executor184 Not tainted 5.15.179-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 : bio_associate_blkg_from_css+0xfc/0x870 block/blk-cgroup.c:1868
lr : bio_associate_blkg_from_css+0xd8/0x870 block/blk-cgroup.c:1865
sp : ffff80001d6e7420
x29: ffff80001d6e7460 x28: dfff800000000000 x27: 1fffe00019a63cc2
x26: 1fffe00019a63cc9 x25: 0000000000000000 x24: ffff0000cd31e648
x23: ffff80001b994b90 x22: ffff800014d69920 x21: 00000000000005e8
x20: ffff0000cd31e608 x19: 1fffe00019a63cc1 x18: ffff80001d6e6c20
x17: 0000000000000000 x16: ffff8000082eb59c x15: ffff800008a19130
x14: 1ffff0000296e06c x13: dfff800000000000 x12: 000000001b758341
x11: 0000000000000000 x10: 0000000000000000 x9 : ffff0000d9038000
x8 : 00000000000000bd x7 : ffff80000a91d220 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : ffff80001b994a80 x0 : ffff0000cd31e600
Call trace:
 bio_associate_blkg_from_css+0xfc/0x870 block/blk-cgroup.c:1868
 bio_associate_blkg+0x238/0x360 block/blk-cgroup.c:1894
 lbmStartIO+0x1b0/0x430 fs/jfs/jfs_logmgr.c:2130
 lbmWrite+0x320/0x404 fs/jfs/jfs_logmgr.c:2079
 lmNextPage+0x2f0/0x860 fs/jfs/jfs_logmgr.c:-1
 lmWriteRecord+0xb84/0xfb0 fs/jfs/jfs_logmgr.c:537
 lmLogSync+0x41c/0x98c fs/jfs/jfs_logmgr.c:977
 jfs_syncpt+0x74/0x98 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+0x108/0x128 fs/super.c:366
 cleanup_mnt+0x3c0/0x474 fs/namespace.c:1143
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1150
 task_work_run+0x130/0x1e4 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946
 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+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
 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: 977eee74 f9400288 9117a115 d343fea8 (387c6908) 
---[ end trace 313e34fa24076be2 ]---
----------------
Code disassembly (best guess):
   0:	977eee74 	bl	0xfffffffffdfbb9d0
   4:	f9400288 	ldr	x8, [x20]
   8:	9117a115 	add	x21, x8, #0x5e8
   c:	d343fea8 	lsr	x8, x21, #3
* 10:	387c6908 	ldrb	w8, [x8, x28] <-- trapping instruction