syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 1 UID: 0 PID: 5836 Comm: syz-executor173 Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline]
RIP: 0010:lmLogSync+0x1f1/0x9d0 fs/jfs/jfs_logmgr.c:937
Code: 86 83 fe 4d 8d 7e d8 4c 89 f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 2d 7f e5 fe 4d 8b 3f 49 83 c7 30 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 ff e8 11 7f e5 fe 49 8b 3f e8 49 cd b9 fe
RSP: 0018:ffffc90001577a40 EFLAGS: 00010216
RAX: 0000000000000006 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff888033028000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001577b48 R08: 0000000000000003 R09: ffffc90001577aa0
R10: dffffc0000000000 R11: fffff520002aef58 R12: ffff88805f1d5000
R13: dffffc0000000000 R14: ffff88807d027238 R15: 0000000000000030
FS:  0000555568909380(0000) GS:ffff8881261c7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8fed3d1000 CR3: 000000005e6bb000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 jfs_syncpt+0x7b/0x90 fs/jfs/jfs_logmgr.c:1041
 jfs_sync_fs+0x87/0xa0 fs/jfs/super.c:650
 sync_filesystem+0xee/0x230 fs/sync.c:56
 generic_shutdown_super+0x6f/0x2c0 fs/super.c:621
 kill_block_super+0x44/0x90 fs/super.c:1710
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1431
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 ptrace_notify+0x281/0x2c0 kernel/signal.c:2520
 ptrace_report_syscall include/linux/ptrace.h:415 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
 syscall_exit_work+0xc2/0x1d0 kernel/entry/common.c:173
 syscall_exit_to_user_mode_prepare+0x6f/0xe0 kernel/entry/common.c:200
 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
 syscall_exit_to_user_mode+0x12/0x120 kernel/entry/common.c:218
 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f887e220977
Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd76b73368 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 000000000001617b RCX: 00007f887e220977
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd76b73420
RBP: 00007ffd76b73420 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffd76b74490
R13: 000055556890a6c0 R14: 431bde82d7b634db R15: 00007ffd76b744b0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline]
RIP: 0010:lmLogSync+0x1f1/0x9d0 fs/jfs/jfs_logmgr.c:937
Code: 86 83 fe 4d 8d 7e d8 4c 89 f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 2d 7f e5 fe 4d 8b 3f 49 83 c7 30 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 ff e8 11 7f e5 fe 49 8b 3f e8 49 cd b9 fe
RSP: 0018:ffffc90001577a40 EFLAGS: 00010216
RAX: 0000000000000006 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff888033028000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001577b48 R08: 0000000000000003 R09: ffffc90001577aa0
R10: dffffc0000000000 R11: fffff520002aef58 R12: ffff88805f1d5000
R13: dffffc0000000000 R14: ffff88807d027238 R15: 0000000000000030
FS:  0000555568909380(0000) GS:ffff8881261c7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d5cc9f4178 CR3: 000000005e6bb000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	86 83 fe 4d 8d 7e    	xchg   %al,0x7e8d4dfe(%rbx)
   6:	d8 4c 89 f8          	fmuls  -0x8(%rcx,%rcx,4)
   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 2d 7f e5 fe       	call   0xfee57f49
  1c:	4d 8b 3f             	mov    (%r15),%r15
  1f:	49 83 c7 30          	add    $0x30,%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 11 7f e5 fe       	call   0xfee57f49
  38:	49 8b 3f             	mov    (%r15),%rdi
  3b:	e8 49 cd b9 fe       	call   0xfeb9cd89