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: 6562 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:jfs_flush_journal+0x9a2/0xec0 fs/jfs/jfs_logmgr.c:1582
Code: 91 ae fe 4d 8d 75 f0 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 ac dc d8 fe 4d 8b 36 49 83 c6 40 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 f7 e8 90 dc d8 fe 49 8b 3e e8 c8 90 ae fe
RSP: 0018:ffffc90003b17b20 EFLAGS: 00010202
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: 9c4b7f9e5ab46a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003b17c50 R08: 0000000000000004 R09: 0000000000000004
R10: ffffc90003b17a44 R11: fffff52000762f51 R12: 0000000000000000
R13: ffff88802140e038 R14: 0000000000000040 R15: ffff8880789e7228
FS:  000055556e70f500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e5357f14a0 CR3: 000000007b3d0000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 jfs_umount+0x178/0x3c0 fs/jfs/jfs_umount.c:58
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x134/0x2b0 fs/super.c:693
 kill_block_super+0x44/0x90 fs/super.c:1660
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 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+0xee/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+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb72f79bf17
Code: a2 c7 05 7c 96 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fffd45c6778 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fb72f80471f RCX: 00007fb72f79bf17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffd45c6830
RBP: 00007fffd45c6830 R08: 00007fffd45c7830 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffd45c78c0
R13: 00007fb72f80471f R14: 000000000005f8bc R15: 00007fffd45c7900
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:write_special_inodes fs/jfs/jfs_logmgr.c:208 [inline]
RIP: 0010:jfs_flush_journal+0x9a2/0xec0 fs/jfs/jfs_logmgr.c:1582
Code: 91 ae fe 4d 8d 75 f0 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 ac dc d8 fe 4d 8b 36 49 83 c6 40 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 f7 e8 90 dc d8 fe 49 8b 3e e8 c8 90 ae fe
RSP: 0018:ffffc90003b17b20 EFLAGS: 00010202
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: 9c4b7f9e5ab46a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003b17c50 R08: 0000000000000004 R09: 0000000000000004
R10: ffffc90003b17a44 R11: fffff52000762f51 R12: 0000000000000000
R13: ffff88802140e038 R14: 0000000000000040 R15: ffff8880789e7228
FS:  000055556e70f500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e54d62f000 CR3: 000000007b3d0000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	91                   	xchg   %eax,%ecx
   1:	ae                   	scas   %es:(%rdi),%al
   2:	fe 4d 8d             	decb   -0x73(%rbp)
   5:	75 f0                	jne    0xfffffff7
   7:	4c 89 f0             	mov    %r14,%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 f7             	mov    %r14,%rdi
  17:	e8 ac dc d8 fe       	call   0xfed8dcc8
  1c:	4d 8b 36             	mov    (%r14),%r14
  1f:	49 83 c6 40          	add    $0x40,%r14
  23:	4c 89 f0             	mov    %r14,%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 f7             	mov    %r14,%rdi
  33:	e8 90 dc d8 fe       	call   0xfed8dcc8
  38:	49 8b 3e             	mov    (%r14),%rdi
  3b:	e8 c8 90 ae fe       	call   0xfeae9108