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@xxxxxxxxxx>
> Fixes: 24e16e385f22 ("ovl: add support for appending lowerdirs one by
> one")
> Cc: <stable@xxxxxxxxxxxxxxx> # v6.7
> Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Reviewed-by: Alexander Larsson <alexl@xxxxxxxxxx>
> return ERR_PTR(-EINVAL);
> }
>
> + if (ctx->nr == ctx->nr_data) {
> + pr_err("at least one non-data lowerdir is
> required\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> err = -EINVAL;
> for (i = 0; i < ctx->nr; i++) {
> l = &ctx->lower[i];
--
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Alexander Larsson Red Hat,
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He's an obese crooked filmmaker trapped in a world he never made. She's
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