loop0: detected capacity change from 0 to 512
EXT4-fs (loop0): mounted filesystem without journal. Quota mode: writeback.
general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 PID: 2675 Comm: syz.0.734 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__ext4_journal_get_write_access+0xad/0x6c0 fs/ext4/ext4_jbd2.c:231
Code: 8c ff 49 8d 5e 30 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 a1 db d1 ff 48 8b 1b 48 83 c3 38 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 84 db d1 ff 4c 8b 23 4d 85 e4 4c
RSP: 0018:ffffc90010cef680 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: 0000000000080000
RDX: ffffc900012d9000 RSI: 0000000000002155 RDI: 0000000000002156
RBP: ffffc90010cef750 R08: ffff88810a97c1f8 R09: 0000000000000001
R10: dffffc0000000000 R11: ffffed1027a26c51 R12: ffffc90010cef7e0
R13: dffffc0000000000 R14: ffff88810a97c1f8 R15: 1ffff9200219ded8
FS:  00007f5533e776c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2efe4d CR3: 000000013d931000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_sample_last_mounted fs/ext4/file.c:822 [inline]
 ext4_file_open+0x57a/0x750 fs/ext4/file.c:846
 do_dentry_open+0x88e/0x1260 fs/open.c:884
 vfs_open+0x73/0x80 fs/open.c:1017
 do_open fs/namei.c:3633 [inline]
 path_openat+0x2700/0x2f80 fs/namei.c:3790
 do_filp_open+0x1f1/0x430 fs/namei.c:3817
 do_sys_openat2+0x15e/0x810 fs/open.c:1343
 do_sys_open fs/open.c:1359 [inline]
 __do_sys_openat fs/open.c:1375 [inline]
 __se_sys_openat fs/open.c:1370 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1370
 x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5532f9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5533e77028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5533215fa0 RCX: 00007f5532f9ce59
RDX: 0000000000183042 RSI: 0000200000000200 RDI: ffffffffffffff9c
RBP: 00007f5533032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000025 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5533216038 R14: 00007f5533215fa0 R15: 00007ffef5346088
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__ext4_journal_get_write_access+0xad/0x6c0 fs/ext4/ext4_jbd2.c:231
Code: 8c ff 49 8d 5e 30 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 a1 db d1 ff 48 8b 1b 48 83 c3 38 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 84 db d1 ff 4c 8b 23 4d 85 e4 4c
RSP: 0018:ffffc90010cef680 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: 0000000000080000
RDX: ffffc900012d9000 RSI: 0000000000002155 RDI: 0000000000002156
RBP: ffffc90010cef750 R08: ffff88810a97c1f8 R09: 0000000000000001
R10: dffffc0000000000 R11: ffffed1027a26c51 R12: ffffc90010cef7e0
R13: dffffc0000000000 R14: ffff88810a97c1f8 R15: 1ffff9200219ded8
FS:  00007f5533e776c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b5c9ea2f8 CR3: 000000013d931000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	8c ff                	mov    %?,%edi
   2:	49 8d 5e 30          	lea    0x30(%r14),%rbx
   6:	48 89 d8             	mov    %rbx,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  12:	74 08                	je     0x1c
  14:	48 89 df             	mov    %rbx,%rdi
  17:	e8 a1 db d1 ff       	call   0xffd1dbbd
  1c:	48 8b 1b             	mov    (%rbx),%rbx
  1f:	48 83 c3 38          	add    $0x38,%rbx
  23:	48 89 d8             	mov    %rbx,%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:	48 89 df             	mov    %rbx,%rdi
  34:	e8 84 db d1 ff       	call   0xffd1dbbd
  39:	4c 8b 23             	mov    (%rbx),%r12
  3c:	4d 85 e4             	test   %r12,%r12
  3f:	4c                   	rex.WR