syzbot

loop2: detected capacity change from 0 to 128
EXT4-fs (loop2): mounted filesystem without journal. Quota mode: none.
ext4 filesystem being mounted at /0/file0aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa supports timestamps until 2038-01-19 (0x7fffffff)
BUG: unable to handle page fault for address: ffffffffffffffec
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 7012067 P4D 7012067 PUD 7014067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 362 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path+0x44/0x120 fs/ext4/extents.c:128
Code: 85 db 0f 84 ba 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 f8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 b4 00 00 00 <0f> b7 43 08 c1 e0 04 48 8d 04 40 48 89 45 c0 48 89 5d d0 48 8d 43
RSP: 0018:ffffc900007a75b0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffffffffe4 RCX: ffff888112f7bcc0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffffffffffec
RBP: ffffc900007a75f0 R08: ffff88812355e267 R09: 1ffff110246abc4c
R10: dffffc0000000000 R11: ffffed10246abc4d R12: ffff88812355e2a0
R13: ffffffffffffffe4 R14: dffffc0000000000 R15: dffffc0000000000
FS:  0000555591ab4500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffec CR3: 000000012d16e000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 finish_range+0x22d/0x340 fs/ext4/migrate.c:60
 update_extent_range fs/ext4/migrate.c:83 [inline]
 update_ind_extent_range+0x30d/0x530 fs/ext4/migrate.c:106
 update_dind_extent_range+0x146/0x210 fs/ext4/migrate.c:135
 ext4_ext_migrate+0xa57/0xe60 fs/ext4/migrate.c:529
 __ext4_ioctl fs/ext4/ioctl.c:1399 [inline]
 ext4_ioctl+0x1e4f/0x3ee0 fs/ext4/ioctl.c:1617
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
 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: 0033:0x7f71f839cdd9
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:00007ffcf5ed1648 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f71f8615fa0 RCX: 00007f71f839cdd9
RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000004
RBP: 00007f71f8432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f71f8615fac R14: 00007f71f8615fa0 R15: 00007f71f8615fa0
 </TASK>
Modules linked in:
CR2: ffffffffffffffec
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path+0x44/0x120 fs/ext4/extents.c:128
Code: 85 db 0f 84 ba 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 f8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 b4 00 00 00 <0f> b7 43 08 c1 e0 04 48 8d 04 40 48 89 45 c0 48 89 5d d0 48 8d 43
RSP: 0018:ffffc900007a75b0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffffffffe4 RCX: ffff888112f7bcc0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffffffffffec
RBP: ffffc900007a75f0 R08: ffff88812355e267 R09: 1ffff110246abc4c
R10: dffffc0000000000 R11: ffffed10246abc4d R12: ffff88812355e2a0
R13: ffffffffffffffe4 R14: dffffc0000000000 R15: dffffc0000000000
FS:  0000555591ab4500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffec CR3: 000000012d16e000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	85 db                	test   %ebx,%ebx
   2:	0f 84 ba 00 00 00    	je     0xc2
   8:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
   f:	fc ff df
  12:	48 8d 7b 08          	lea    0x8(%rbx),%rdi
  16:	48 89 f8             	mov    %rdi,%rax
  19:	48 c1 e8 03          	shr    $0x3,%rax
  1d:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax
  22:	84 c0                	test   %al,%al
  24:	0f 85 b4 00 00 00    	jne    0xde
* 2a:	0f b7 43 08          	movzwl 0x8(%rbx),%eax <-- trapping instruction
  2e:	c1 e0 04             	shl    $0x4,%eax
  31:	48 8d 04 40          	lea    (%rax,%rax,2),%rax
  35:	48 89 45 c0          	mov    %rax,-0x40(%rbp)
  39:	48 89 5d d0          	mov    %rbx,-0x30(%rbp)
  3d:	48                   	rex.W
  3e:	8d                   	.byte 0x8d
  3f:	43                   	rex.XB