ERROR: (device loop0): txBegin: read-only filesystem
ERROR: (device loop0): remounting filesystem as read-only
jfs_dirty_inode called on read-only volume
Is remount racy?
Oops: general protection fault, probably for non-canonical address 0xdffffc00000000f3: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000798-0x000000000000079f]
CPU: 1 UID: 0 PID: 6967 Comm: syz.0.170 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline]
RIP: 0010:txEnd+0xb4/0x530 fs/jfs/jfs_txnmgr.c:507
Code: 49 8d 5e 20 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 6c 07 e1 fe 41 bf 98 07 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 4d 07 e1 fe 49 8b 1f 48 83 c3 30
RSP: 0018:ffffc9000d097ac0 EFLAGS: 00010206
RAX: 00000000000000f3 RBX: ffffc90003209020 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff8ce0014e RDI: 00000000ffffffff
RBP: ffffc9000d097d58 R08: ffffffff8eda8877 R09: 1ffffffff1db510e
R10: dffffc0000000000 R11: fffffbfff1db510f R12: ffff88805a77f810
R13: dffffc0000000000 R14: ffffc90003209000 R15: 0000000000000798
FS:  00007fe3b3b5e6c0(0000) GS:ffff888126e12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e3c7a98660 CR3: 0000000028ab0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 jfs_create+0x33e/0xa80 fs/jfs/namei.c:159
 vfs_create+0x3b2/0x410 fs/namei.c:4132
 do_mknodat+0x3ee/0x620 fs/namei.c:5039
 __do_sys_mknodat fs/namei.c:5071 [inline]
 __se_sys_mknodat fs/namei.c:5068 [inline]
 __x64_sys_mknodat+0xa7/0xc0 fs/namei.c:5068
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe3b58ff749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe3b3b5e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007fe3b5b55fa0 RCX: 00007fe3b58ff749
RDX: 0000000000000000 RSI: 0000200000000140 RDI: ffffffffffffff9c
RBP: 00007fe3b5983f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3b5b56038 R14: 00007fe3b5b55fa0 R15: 00007fff723353f8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline]
RIP: 0010:txEnd+0xb4/0x530 fs/jfs/jfs_txnmgr.c:507
Code: 49 8d 5e 20 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 6c 07 e1 fe 41 bf 98 07 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 4d 07 e1 fe 49 8b 1f 48 83 c3 30
RSP: 0018:ffffc9000d097ac0 EFLAGS: 00010206
RAX: 00000000000000f3 RBX: ffffc90003209020 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff8ce0014e RDI: 00000000ffffffff
RBP: ffffc9000d097d58 R08: ffffffff8eda8877 R09: 1ffffffff1db510e
R10: dffffc0000000000 R11: fffffbfff1db510f R12: ffff88805a77f810
R13: dffffc0000000000 R14: ffffc90003209000 R15: 0000000000000798
FS:  00007fe3b3b5e6c0(0000) GS:ffff888126e12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e3c7a98660 CR3: 0000000028ab0000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	49 8d 5e 20          	lea    0x20(%r14),%rbx
   4:	48 89 d8             	mov    %rbx,%rax
   7:	48 c1 e8 03          	shr    $0x3,%rax
   b:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  10:	74 08                	je     0x1a
  12:	48 89 df             	mov    %rbx,%rdi
  15:	e8 6c 07 e1 fe       	call   0xfee10786
  1a:	41 bf 98 07 00 00    	mov    $0x798,%r15d
  20:	4c 03 3b             	add    (%rbx),%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 ff             	mov    %r15,%rdi
  34:	e8 4d 07 e1 fe       	call   0xfee10786
  39:	49 8b 1f             	mov    (%r15),%rbx
  3c:	48 83 c3 30          	add    $0x30,%rbx