Follow symlinks in MkdirAllAt

ekzhang · ekzhang · commit b879b152bfee · 2025-07-10T14:47:18.000-04:00
See #11910 for details — this potentially fixes a divergence between gVisor and runc behavior where having the `cwd` of the OCI container spec set to a symlink to a folder causes gVisor to exit with this error: ``` running container: starting container: starting root container: starting sandbox: failed to create process working directory "/cwd-folder-name-here": not a directory ```
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
@@ -877,6 +877,7 @@ func (vfs *VirtualFilesystem) MkdirAllAt(ctx context.Context, currentPath string
 		Root:  root,
 		Start: root,
 		Path:  fspath.Parse(currentPath),
+		FollowFinalSymlink: true,
 	}
 	stat, err := vfs.StatAt(ctx, creds, pop, &StatOptions{Mask: linux.STATX_TYPE})
 	switch {

Original file line number	Diff line number	Diff line change
`@@ -877,6 +877,7 @@ func (vfs *VirtualFilesystem) MkdirAllAt(ctx context.Context, currentPath string`
`877`	`877`	`Root: root,`
`878`	`878`	`Start: root,`
`879`	`879`	`Path: fspath.Parse(currentPath),`
	`880`	`+ FollowFinalSymlink: true,`
`880`	`881`	`}`
`881`	`882`	`stat, err := vfs.StatAt(ctx, creds, pop, &StatOptions{Mask: linux.STATX_TYPE})`
`882`	`883`	`switch {`