Add permission checks to vfs2 truncate.

- Check write permission on truncate(2). Unlike ftruncate(2),
  truncate(2) fails if the user does not have write permissions
  on the file.
- For gofers under InteropModeShared, check file type before
  making a truncate request. We should fail early and avoid
  making an rpc when possible. Furthermore, depending on the
  remote host's failure may give us unexpected behavior--if the
  host converts the truncate request to an ftruncate syscall on
  an open fd, we will get EINVAL instead of EISDIR.

Updates #2923.

PiperOrigin-RevId: 322913569

1 files changed, 1 insertions, 1 deletions

diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index 491495b16..00e3c99cd 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -1334,7 +1334,7 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts
 		fs.renameMuRUnlockAndCheckCaching(&ds)
 		return err
 	}
-	if err := d.setStat(ctx, rp.Credentials(), &opts.Stat, rp.Mount()); err != nil {
+	if err := d.setStat(ctx, rp.Credentials(), &opts, rp.Mount()); err != nil {
 		fs.renameMuRUnlockAndCheckCaching(&ds)
 		return err
 	}