From 6f7e2bb388cb29a355dece8921671c0085f53ea9 Mon Sep 17 00:00:00 2001 From: Michael Pratt Date: Wed, 17 Jul 2019 16:10:44 -0700 Subject: Take copyMu in Revalidate copyMu is required to read child.overlay.upper. PiperOrigin-RevId: 258662209 --- pkg/sentry/fs/mount_overlay.go | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'pkg/sentry/fs') diff --git a/pkg/sentry/fs/mount_overlay.go b/pkg/sentry/fs/mount_overlay.go index 4fcdd6c01..299712cd7 100644 --- a/pkg/sentry/fs/mount_overlay.go +++ b/pkg/sentry/fs/mount_overlay.go @@ -66,13 +66,17 @@ func (o *overlayMountSourceOperations) Revalidate(ctx context.Context, name stri panic("an overlay cannot revalidate file objects from the lower fs") } - // Do we have anything to revalidate? - if child.overlay.upper == nil { - return false + var revalidate bool + child.overlay.copyMu.RLock() + if child.overlay.upper != nil { + // Does the upper require revalidation? + revalidate = o.upper.Revalidate(ctx, name, parent.overlay.upper, child.overlay.upper) + } else { + // Nothing to revalidate. + revalidate = false } - - // Does the upper require revalidation? - return o.upper.Revalidate(ctx, name, parent.overlay.upper, child.overlay.upper) + child.overlay.copyMu.RUnlock() + return revalidate } // Keep implements MountSourceOperations by delegating to the upper -- cgit v1.2.3