Docker Desktop crashes on startup with disk.extend panic after update

[EmanuelFaria]

Description

Docker Desktop crashes immediately on startup with a disk service panic. This started after what appears to be an automatic update around January 21, 2026.

Error Message

service disk panicked: map[], stack: goroutine 83 [running]:
runtime/debug.Stack()
    runtime/debug/stack.go:26 +0x64
github.com/docker/pinata/linuxkit/pkg/services.runServers.func1.1()
    github.com/docker/pinata/linuxkit/pkg/services/start.go:106 +0x74
panic({0x2333700?, 0x40022080a8?})
    runtime/panic.go:783 +0x120
github.com/docker/pinata/linuxkit/pkg/initd/disk.extend({0x24b4020, 0x40006d95e0}, {0x40006d0588, 0x8})
    github.com/docker/pinata/linuxkit/pkg/initd/disk/extend.go:41 +0x610
github.com/docker/pinata/linuxkit/pkg/initd/disk.mountReadWriteDisk({0x24b4020, 0x40006d95e0}, {0x19d0a54, 0x8})
    github.com/docker/pinata/linuxkit/pkg/initd/disk/mount.go:43 +0xd8
github.com/docker/pinata/linuxkit/pkg/initd/disk.Mount({0x24b4020, 0x40006d95e0})
    github.com/docker/pinata/linuxkit/pkg/initd/disk/mount.go:18 +0x5c

Diagnostics ID

7FBB2274-A578-455B-B24F-96EF6B402411/20260123031528

Environment

• OS: macOS (Apple Silicon / ARM64)
• Docker Desktop versions tested: Latest (crashed), v4.56.0 (also crashes with same error)
• Docker.raw last modified: Jan 21, 2026 at 11:42 PM

Steps to Reproduce

1. Docker Desktop was working normally
2. Noticed Docker showing "starting" but never completing (for several days)
3. Attempted to restart Docker - crashes with above panic
4. Downgraded to v4.56.0 - same crash
5. Docker.raw file exists (7.3TB sparse file) but appears to have filesystem corruption

Expected Behavior

Docker Desktop should start normally, or at minimum provide a recovery option for corrupted disk images.

Additional Context

• The crash occurs during the disk mount/extend phase
• Unable to repair Docker.raw using macOS tools (ext4 filesystem)
• Factory reset appears to be the only option, resulting in complete data loss