general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 PID: 4578 Comm: gfs2_quotad Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:do_sync+0x993/0xc40 fs/gfs2/quota.c:986
Code: 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 c5 10 3a fe 48 8b 1b 48 8d 7b 10 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 05 e8 a2 10 3a fe 48 8b 7b 10 48 89 de ba 02 00 04
RSP: 0018:ffffc90003707ba0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000010
RBP: ffffc90003707d08 R08: ffffffff90af5357 R09: 1ffffffff215ea6a
R10: dffffc0000000000 R11: fffffbfff215ea6b R12: ffff88805ddf7238
R13: 00000000fffffffb R14: ffffffffffffffff R15: ffff88805aad2000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8c09be7f18 CR3: 000000005d03f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 gfs2_quota_sync+0x32c/0x700 fs/gfs2/quota.c:1329
 quotad_check_timeo fs/gfs2/quota.c:1519 [inline]
 gfs2_quotad+0x420/0x680 fs/gfs2/quota.c:1566
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_sync+0x993/0xc40 fs/gfs2/quota.c:986
Code: 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 c5 10 3a fe 48 8b 1b 48 8d 7b 10 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 05 e8 a2 10 3a fe 48 8b 7b 10 48 89 de ba 02 00 04
RSP: 0018:ffffc90003707ba0 EFLAGS: 00010202

RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000010
RBP: ffffc90003707d08 R08: ffffffff90af5357 R09: 1ffffffff215ea6a
R10: dffffc0000000000 R11: fffffbfff215ea6b R12: ffff88805ddf7238
R13: 00000000fffffffb R14: ffffffffffffffff R15: ffff88805aad2000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1581280e9c CR3: 000000007e002000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)
   4:	74 08                	je     0xe
   6:	48 89 df             	mov    %rbx,%rdi
   9:	e8 c5 10 3a fe       	call   0xfe3a10d3
   e:	48 8b 1b             	mov    (%rbx),%rbx
  11:	48 8d 7b 10          	lea    0x10(%rbx),%rdi
  15:	48 89 f8             	mov    %rdi,%rax
  18:	48 c1 e8 03          	shr    $0x3,%rax
  1c:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  23:	fc ff df
* 26:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2a:	74 05                	je     0x31
  2c:	e8 a2 10 3a fe       	call   0xfe3a10d3
  31:	48 8b 7b 10          	mov    0x10(%rbx),%rdi
  35:	48 89 de             	mov    %rbx,%rsi
  38:	ba                   	.byte 0xba
  39:	02 00                	add    (%rax),%al
  3b:	04                   	.byte 0x4