From: Chris Webb <chris@arachsys.com>
Date: Mon, 24 Apr 2023 16:14:47 +0000 (+0100)
Subject: libmount: Don't silently accept an X-mount.idmap with only whitespace
X-Git-Tag: v2.39~60
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=13e267f722f36e5fa7db94f22b6082a6864920e1;p=thirdparty%2Futil-linux.git

libmount: Don't silently accept an X-mount.idmap with only whitespace

X-mount.idmap accepts a series of whitespace-separated tokens. We reject
an empty argument but silently accept an argument consisting of whitespace
with no tokens. Test for the empty case more thoroughly.

[kzak@redhat.com: - use skip_blank()]

Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libmount/src/hook_idmap.c b/libmount/src/hook_idmap.c
index affd8fb144..2e01ef4445 100644
--- a/libmount/src/hook_idmap.c
+++ b/libmount/src/hook_idmap.c
@@ -387,9 +387,11 @@ static int hook_prepare_options(
 	opt = mnt_optlist_get_named(ol, "X-mount.idmap", cxt->map_userspace);
 	if (!opt)
 		return 0;
-	value = mnt_opt_get_value(opt);
 
-	if (!value)
+	value = mnt_opt_get_value(opt);
+	if (value)
+		value = skip_blank(p);
+	if (!value || !*value)
 		return errno = EINVAL, -MNT_ERR_MOUNTOPT;
 
 	hd = new_hook_data();