syzbot

general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 1 PID: 5911 Comm: syz-executor Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:write_special_inodes fs/jfs/jfs_logmgr.c:208 [inline]
RIP: 0010:lmLogSync+0x22f/0x9c0 fs/jfs/jfs_logmgr.c:937
Code: 72 b3 fe 4d 8d 7e f0 4c 89 f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 6f 4e dd 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 53 4e dd fe 49 8b 3f e8 db 71 b3 fe
RSP: 0018:ffffc90003407b80 EFLAGS: 00010202
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: c83bb5383f339300
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003407c88 R08: ffffc90003407ae7 R09: 0000000000000000
R10: ffffc90003407aa0 R11: fffff52000680f5d R12: ffff88802f171800
R13: dffffc0000000000 R14: ffff8880246c1038 R15: 0000000000000040
FS:  0000555583ebe500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c007962000 CR3: 0000000030902000 CR4: 00000000003506e0
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:1250
 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+0xb1/0x140 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: 0033:0x7f8a5af8ff17
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:00007ffe7d3a37a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f8a5b011c05 RCX: 00007f8a5af8ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe7d3a3860
RBP: 00007ffe7d3a3860 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe7d3a48f0
R13: 00007f8a5b011c05 R14: 000000000001f6a2 R15: 00007ffe7d3a4930
 </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: 72 b3 fe 4d 8d 7e f0 4c 89 f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 6f 4e dd 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 53 4e dd fe 49 8b 3f e8 db 71 b3 fe
RSP: 0018:ffffc90003407b80 EFLAGS: 00010202
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: c83bb5383f339300
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003407c88 R08: ffffc90003407ae7 R09: 0000000000000000
R10: ffffc90003407aa0 R11: fffff52000680f5d R12: ffff88802f171800
R13: dffffc0000000000 R14: ffff8880246c1038 R15: 0000000000000040
FS:  0000555583ebe500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faf9ea16000 CR3: 0000000030902000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	72 b3                	jb     0xffffffb5
   2:	fe 4d 8d             	decb   -0x73(%rbp)
   5:	7e f0                	jle    0xfffffff7
   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 6f 4e dd fe       	call   0xfedd4e8b
  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 53 4e dd fe       	call   0xfedd4e8b
  38:	49 8b 3f             	mov    (%r15),%rdi
  3b:	e8 db 71 b3 fe       	call   0xfeb3721b