syzbot

general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 0 PID: 5910 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:write_special_inodes fs/jfs/jfs_logmgr.c:208 [inline]
RIP: 0010:lmLogSync+0x22f/0x9c0 fs/jfs/jfs_logmgr.c:937
Code: cc b2 fe 4d 8d 7e f0 4c 89 f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 0f ca dc fe 4d 8b 3f 49 83 c7 40 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 ff e8 f3 c9 dc fe 49 8b 3f e8 4b cc b2 fe
RSP: 0018:ffffc90003367b80 EFLAGS: 00010202
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: a48d769b6f99fc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003367c88 R08: ffffc90003367ae7 R09: 0000000000000000
R10: ffffc90003367aa0 R11: fffff5200066cf5d R12: ffff88807ad65000
R13: dffffc0000000000 R14: ffff88802507c438 R15: 0000000000000040
FS:  000055558f455500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1372b4a000 CR3: 000000002d2df000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 jfs_syncpt+0x7b/0x90 fs/jfs/jfs_logmgr.c:1041
 jfs_sync_fs+0x87/0xa0 fs/jfs/super.c:685
 sync_filesystem+0xea/0x220 fs/sync.c:56
 generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
 kill_block_super+0x44/0x90 fs/super.c:1660
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1259
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff377790a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe6db182e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff377813d7d RCX: 00007ff377790a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe6db183a0
RBP: 00007ffe6db183a0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe6db19430
R13: 00007ff377813d7d R14: 000000000001f035 R15: 00007ffe6db19470
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:write_special_inodes fs/jfs/jfs_logmgr.c:208 [inline]
RIP: 0010:lmLogSync+0x22f/0x9c0 fs/jfs/jfs_logmgr.c:937
Code: cc b2 fe 4d 8d 7e f0 4c 89 f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 0f ca dc fe 4d 8b 3f 49 83 c7 40 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 ff e8 f3 c9 dc fe 49 8b 3f e8 4b cc b2 fe
RSP: 0018:ffffc90003367b80 EFLAGS: 00010202
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: a48d769b6f99fc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003367c88 R08: ffffc90003367ae7 R09: 0000000000000000
R10: ffffc90003367aa0 R11: fffff5200066cf5d R12: ffff88807ad65000
R13: dffffc0000000000 R14: ffff88802507c438 R15: 0000000000000040
FS:  000055558f455500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1372b48000 CR3: 000000002d2df000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	cc                   	int3
   1:	b2 fe                	mov    $0xfe,%dl
   3:	4d 8d 7e f0          	lea    -0x10(%r14),%r15
   7:	4c 89 f8             	mov    %r15,%rax
   a:	48 c1 e8 03          	shr    $0x3,%rax
   e:	80 3c 18 00          	cmpb   $0x0,(%rax,%rbx,1)
  12:	74 08                	je     0x1c
  14:	4c 89 ff             	mov    %r15,%rdi
  17:	e8 0f ca dc fe       	call   0xfedcca2b
  1c:	4d 8b 3f             	mov    (%r15),%r15
  1f:	49 83 c7 40          	add    $0x40,%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 18 00          	cmpb   $0x0,(%rax,%rbx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 ff             	mov    %r15,%rdi
  33:	e8 f3 c9 dc fe       	call   0xfedcca2b
  38:	49 8b 3f             	mov    (%r15),%rdi
  3b:	e8 4b cc b2 fe       	call   0xfeb2cc8b