diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2025-02-10 15:11:22 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-25 10:47:53 +0200 |
| commit | b9e3579213ba648fa23f780e8d53e99011c62331 (patch) | |
| tree | bf959392a4dc2c916debbbe69827891b95bfdd8d | |
| parent | 029458063ebb291eca467cd0989dd1d6b7b8ab90 (diff) | |
ovl: don't allow datadir only
commit eb3a04a8516ee9b5174379306f94279fc90424c4 upstream.
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>
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/overlayfs/super.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index fe511192f83c..87a36c6eea5f 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1119,6 +1119,11 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, 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]; |