blkno = 8ed2c, nblocks = 1
ERROR: (device loop0): dbUpdatePMap: blocks are outside the map
ERROR: (device loop0): remounting filesystem as read-only
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 102 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:metapage_write_folio+0xa8/0xca0 fs/jfs/jfs_metapage.c:428
Code: e8 5d 44 7d fe 4d 8d 74 24 18 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 e2 2e e2 fe 4d 8b 36 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 c9 2e e2 fe 49 8b 1e 4d 8d 74 24
RSP: 0018:ffffc900018c77c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffffd40002971e6 RCX: ffff88801c794880
RDX: 0000000000000000 RSI: ffffc900018c7920 RDI: ffffea00014b8f00
RBP: ffffc900018c78d0 R08: ffffea00014b8f37 R09: 1ffffd40002971e6
R10: dffffc0000000000 R11: fffff940002971e7 R12: ffffea00014b8f00
R13: 0000000000000081 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88808d210000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f32821ff000 CR3: 0000000042b5e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 metapage_write_one+0x24c/0x450 fs/jfs/jfs_metapage.c:818
 release_metapage+0x5be/0xac0 fs/jfs/jfs_metapage.c:884
 txUnlock+0x524/0xdf0 fs/jfs/jfs_txnmgr.c:947
 txLazyCommit fs/jfs/jfs_txnmgr.c:2682 [inline]
 jfs_lazycommit+0x584/0xa90 fs/jfs/jfs_txnmgr.c:2733
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:metapage_write_folio+0xa8/0xca0 fs/jfs/jfs_metapage.c:428
Code: e8 5d 44 7d fe 4d 8d 74 24 18 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 e2 2e e2 fe 4d 8b 36 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 c9 2e e2 fe 49 8b 1e 4d 8d 74 24
RSP: 0018:ffffc900018c77c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffffd40002971e6 RCX: ffff88801c794880
RDX: 0000000000000000 RSI: ffffc900018c7920 RDI: ffffea00014b8f00
RBP: ffffc900018c78d0 R08: ffffea00014b8f37 R09: 1ffffd40002971e6
R10: dffffc0000000000 R11: fffff940002971e7 R12: ffffea00014b8f00
R13: 0000000000000081 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88808d210000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f328d3ec470 CR3: 000000001263a000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	e8 5d 44 7d fe       	call   0xfe7d4462
   5:	4d 8d 74 24 18       	lea    0x18(%r12),%r14
   a:	4c 89 f0             	mov    %r14,%rax
   d:	48 c1 e8 03          	shr    $0x3,%rax
  11:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
  16:	74 08                	je     0x20
  18:	4c 89 f7             	mov    %r14,%rdi
  1b:	e8 e2 2e e2 fe       	call   0xfee22f02
  20:	4d 8b 36             	mov    (%r14),%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 c9 2e e2 fe       	call   0xfee22f02
  39:	49 8b 1e             	mov    (%r14),%rbx
  3c:	4d                   	rex.WRB
  3d:	8d                   	.byte 0x8d
  3e:	74 24                	je     0x64