From 4a7a835c0f5be2170435fe2ca28d1215131d8cc2 Mon Sep 17 00:00:00 2001
From: Neil <neil@stably.ai>
Date: Sun, 20 Sep 2026 22:46:35 -0700
Subject: [PATCH] fix(worktree): refuse the drvfs volume root and the automount
 under a WSL UNC alias

`\\wsl.localhost\Ubuntu\mnt\c` is the whole C: volume and `\\wsl.localhost\Ubuntu\mnt`
holds every drvfs volume. Neither is caught by the root check in
`isDangerousWorktreeRemovalPath` (their win32 root is the distro share) nor by the
Windows-profile rule on the drive form (`C:\` is not `C:\Users`), so both read as
deletable. Measured on a Windows 11 host with WSL2: `rm -rf` inside the distro on the
`/mnt/c` spelling deletes on the Windows drive.
---
 src/main/worktree-removal-home-guard.test.ts |  5 +++++
 src/main/worktree-removal-home-guard.ts      | 11 +++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/main/worktree-removal-home-guard.test.ts b/src/main/worktree-removal-home-guard.test.ts
index 14ab1ac674f..e9e434b2ed2 100644
--- a/src/main/worktree-removal-home-guard.test.ts
+++ b/src/main/worktree-removal-home-guard.test.ts
@@ -93,7 +93,12 @@ describe('path-shape home detection', () => {
     // `C:\Users\bob` wearing a Linux spelling, not a directory in the distro.
     ['\\\\wsl.localhost\\Ubuntu\\mnt\\c\\Users\\bob', true],
     ['\\\\wsl$\\Ubuntu\\mnt\\c\\Users', true],
+    // The volume itself, and the automount that holds every volume, contain the profile.
+    ['\\\\wsl.localhost\\Ubuntu\\mnt\\c', true],
+    ['\\\\wsl.localhost\\Ubuntu\\mnt\\c\\', true],
+    ['\\\\wsl.localhost\\Ubuntu\\mnt', true],
     ['\\\\wsl.localhost\\Ubuntu\\mnt\\c\\Users\\bob\\ws\\wt', false],
+    ['\\\\wsl.localhost\\Ubuntu\\mnt\\c\\src\\repo', false],
     // `/MNT` is an ordinary case-sensitive Linux directory, never the automount.
     ['\\\\wsl.localhost\\Ubuntu\\MNT\\c\\Users\\bob', false]
   ])('WSL drvfs %s -> %s', (worktreePath, expected) => {
diff --git a/src/main/worktree-removal-home-guard.ts b/src/main/worktree-removal-home-guard.ts
index c8466610cc8..7dde11b53d8 100644
--- a/src/main/worktree-removal-home-guard.ts
+++ b/src/main/worktree-removal-home-guard.ts
@@ -189,9 +189,16 @@ function isLikelyWslDistroHomeDirectory(resolvedWorktreePath: string, pathOps: P
   const linuxPath = trimTrailingSlash(wsl.linuxPath)
   const drivePath = toWindowsWslDrivePath(linuxPath)
   if (drivePath) {
-    return isLikelyWindowsUserProfileDirectory(win32.resolve(drivePath), win32)
+    const resolvedDrivePath = win32.resolve(drivePath)
+    // Why: `/mnt/c` is the whole volume. `C:\` is refused as a root before this guard runs; its
+    // drvfs spelling has to be refused here, since its win32 root is the distro share.
+    return (
+      win32.parse(resolvedDrivePath).root === resolvedDrivePath ||
+      isLikelyWindowsUserProfileDirectory(resolvedDrivePath, win32)
+    )
   }
-  return wsl.linuxPath === '/' || isPosixHomeRoot(linuxPath)
+  // Why `/mnt`: the automount parent holds every drvfs volume, so it contains every profile.
+  return wsl.linuxPath === '/' || linuxPath === '/mnt' || isPosixHomeRoot(linuxPath)
 }
 
 function isWslUncRemovalPath(resolvedWorktreePath: string): boolean {