On Tue, 2025-03-25 at 11:46 +0100, Miklos Szeredi wrote:
In theory overlayfs could support upper layer directly referring to a data layer, but there's no current use case for this.
Originally, when data-only layers were introduced, this wasn't allowed, only introduced by the "datadir+" feature, but without actually handling this case, resulting in an Oops.
Fix by disallowing datadir without lowerdir.
Reported-by: Giuseppe Scrivano gscrivan@redhat.com Fixes: 24e16e385f22 ("ovl: add support for appending lowerdirs one by one") Cc: stable@vger.kernel.org # v6.7 Reviewed-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com
Reviewed-by: Alexander Larsson alexl@redhat.com
return ERR_PTR(-EINVAL); }
- if (ctx->nr == ctx->nr_data) {
pr_err("at least one non-data lowerdir isrequired\n");
return ERR_PTR(-EINVAL);- }
err = -EINVAL; for (i = 0; i < ctx->nr; i++) { l = &ctx->lower[i];