general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 17227 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
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+0x2d14/0x6890 fs/ext4/extents.c:4513
Code: 44 24 08 89 18 89 9c 24 38 01 00 00 4c 8b 7c 24 18 4d 85 ff 0f 84 b1 e2 ff ff e8 87 ba 58 ff 49 8d 7f 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 e7 1d 00 00 41 0f b7 47 08 c1 e0 04 48
RSP: 0018:ffffc9000411f520 EFLAGS: 00010246
RAX: 0000000000000000 RBX: fffffffffffffffb RCX: ffff88802d1a5a00
RDX: 0000000000000000 RSI: ffffffff8acacb60 RDI: 0000000000000003
RBP: ffffc9000411f7d0 R08: ffffffff911bc59f R09: 1ffffffff22378b3
R10: dffffc0000000000 R11: fffffbfff22378b4 R12: 0000000000000001
R13: 1ffff92000823ed0 R14: dffffc0000000000 R15: fffffffffffffffb
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fee20bc9000 CR3: 000000002f2ce000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 ext4_map_blocks+0x9db/0x1a90 fs/ext4/inode.c:654
 ext4_convert_unwritten_extents+0x2c0/0x5e0 fs/ext4/extents.c:4944
 ext4_convert_unwritten_io_end_vec+0xff/0x170 fs/ext4/extents.c:4983
 ext4_end_io_end fs/ext4/page-io.c:194 [inline]
 ext4_do_flush_completed_IO fs/ext4/page-io.c:269 [inline]
 ext4_end_io_rsv_work+0x2af/0x640 fs/ext4/page-io.c:283
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Modules linked in:
---[ 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+0x2d14/0x6890 fs/ext4/extents.c:4513
Code: 44 24 08 89 18 89 9c 24 38 01 00 00 4c 8b 7c 24 18 4d 85 ff 0f 84 b1 e2 ff ff e8 87 ba 58 ff 49 8d 7f 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 e7 1d 00 00 41 0f b7 47 08 c1 e0 04 48
RSP: 0018:ffffc9000411f520 EFLAGS: 00010246
RAX: 0000000000000000 RBX: fffffffffffffffb RCX: ffff88802d1a5a00
RDX: 0000000000000000 RSI: ffffffff8acacb60 RDI: 0000000000000003
RBP: ffffc9000411f7d0 R08: ffffffff911bc59f R09: 1ffffffff22378b3
R10: dffffc0000000000 R11: fffffbfff22378b4 R12: 0000000000000001
R13: 1ffff92000823ed0 R14: dffffc0000000000 R15: fffffffffffffffb
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a4844113b8 CR3: 00000000588bb000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	44 24 08             	rex.R and $0x8,%al
   3:	89 18                	mov    %ebx,(%rax)
   5:	89 9c 24 38 01 00 00 	mov    %ebx,0x138(%rsp)
   c:	4c 8b 7c 24 18       	mov    0x18(%rsp),%r15
  11:	4d 85 ff             	test   %r15,%r15
  14:	0f 84 b1 e2 ff ff    	je     0xffffe2cb
  1a:	e8 87 ba 58 ff       	call   0xff58baa6
  1f:	49 8d 7f 08          	lea    0x8(%r15),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 e7 1d 00 00    	jne    0x1e1e
  37:	41 0f b7 47 08       	movzwl 0x8(%r15),%eax
  3c:	c1 e0 04             	shl    $0x4,%eax
  3f:	48                   	rex.W