EXT4-fs error (device loop1): __ext4_ext_dirty:206: inode #2: comm syz.1.1807: mark_inode_dirty error
BUG: unable to handle page fault for address: ffffffffffffff93
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD cf35067 P4D cf35067 PUD cf37067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 13510 Comm: syz.1.1807 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline]
RIP: 0010:ext4_ext_map_blocks+0x2d00/0x6800 fs/ext4/extents.c:4494
Code: 8b 7c 24 10 4d 85 ff 0f 84 bd 00 00 00 e8 78 dc 58 ff 49 8d 7f 08 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 3d 1e 00 00 <41> 0f b7 47 08 c1 e0 04 48 8d 04 40 48 89 44 24 10 4d 89 fc 49 8d
RSP: 0018:ffffc9000350f4a0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000d13b000 RSI: 000000000002d64b RDI: ffffffffffffff93
RBP: ffffc9000350f750 R08: ffff88807818db43 R09: 1ffff1100f031b68
R10: dffffc0000000000 R11: ffffed100f031b69 R12: 0000000000000000
R13: 1ffff920006a1ec0 R14: dffffc0000000000 R15: ffffffffffffff8b
FS:  00007fed9dcd46c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffff93 CR3: 000000005fcbb000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 ext4_map_blocks+0x9e2/0x1b80 fs/ext4/inode.c:652
 ext4_getblk+0x1d0/0x6f0 fs/ext4/inode.c:862
 ext4_bread+0x2a/0x170 fs/ext4/inode.c:918
 ext4_append+0x2c2/0x560 fs/ext4/namei.c:83
 ext4_add_entry+0x9eb/0xd90 fs/ext4/namei.c:2511
 ext4_add_nondir+0x93/0x270 fs/ext4/namei.c:2845
 ext4_create+0x2ea/0x470 fs/ext4/namei.c:2891
 vfs_create+0x1f4/0x360 fs/namei.c:3198
 do_mknodat+0x3d0/0x500 fs/namei.c:4049
 __do_sys_mknod fs/namei.c:4082 [inline]
 __se_sys_mknod fs/namei.c:4080 [inline]
 __x64_sys_mknod+0x8e/0xa0 fs/namei.c:4080
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fed9cd9c819
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:00007fed9dcd4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007fed9d015fa0 RCX: 00007fed9cd9c819
RDX: 0000000000000703 RSI: 0000000000000020 RDI: 0000200000000780
RBP: 00007fed9ce32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fed9d016038 R14: 00007fed9d015fa0 R15: 00007fff452a3b18
 </TASK>
Modules linked in:
CR2: ffffffffffffff93
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline]
RIP: 0010:ext4_ext_map_blocks+0x2d00/0x6800 fs/ext4/extents.c:4494
Code: 8b 7c 24 10 4d 85 ff 0f 84 bd 00 00 00 e8 78 dc 58 ff 49 8d 7f 08 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 3d 1e 00 00 <41> 0f b7 47 08 c1 e0 04 48 8d 04 40 48 89 44 24 10 4d 89 fc 49 8d
RSP: 0018:ffffc9000350f4a0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000d13b000 RSI: 000000000002d64b RDI: ffffffffffffff93
RBP: ffffc9000350f750 R08: ffff88807818db43 R09: 1ffff1100f031b68
R10: dffffc0000000000 R11: ffffed100f031b69 R12: 0000000000000000
R13: 1ffff920006a1ec0 R14: dffffc0000000000 R15: ffffffffffffff8b
FS:  00007fed9dcd46c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffff93 CR3: 000000005fcbb000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	8b 7c 24 10          	mov    0x10(%rsp),%edi
   4:	4d 85 ff             	test   %r15,%r15
   7:	0f 84 bd 00 00 00    	je     0xca
   d:	e8 78 dc 58 ff       	call   0xff58dc8a
  12:	49 8d 7f 08          	lea    0x8(%r15),%rdi
  16:	48 89 f8             	mov    %rdi,%rax
  19:	48 c1 e8 03          	shr    $0x3,%rax
  1d:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax
  22:	84 c0                	test   %al,%al
  24:	0f 85 3d 1e 00 00    	jne    0x1e67
* 2a:	41 0f b7 47 08       	movzwl 0x8(%r15),%eax <-- trapping instruction
  2f:	c1 e0 04             	shl    $0x4,%eax
  32:	48 8d 04 40          	lea    (%rax,%rax,2),%rax
  36:	48 89 44 24 10       	mov    %rax,0x10(%rsp)
  3b:	4d 89 fc             	mov    %r15,%r12
  3e:	49                   	rex.WB
  3f:	8d                   	.byte 0x8d