[PATCH 2/2] cmdlinepart: refuse partitions with empty name

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Running addpart /dev/mmc3 0xe0000@0 currently creates a partition with a
zero-sized name. Check for this condition and throw an error.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 lib/cmdlinepart.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/cmdlinepart.c b/lib/cmdlinepart.c
index afba544965b4..3e8c415c7ea6 100644
--- a/lib/cmdlinepart.c
+++ b/lib/cmdlinepart.c
@@ -30,6 +30,7 @@ int cmdlinepart_do_parse_one(const char *devname, const char *partstr,
 	char *end;
 	char buf[PATH_MAX] = {};
 	unsigned long flags = DEVFS_PARTITION_FOR_FIXUP;
+	size_t partname_len = 0;
 	struct cdev *cdev;
 
 	memset(buf, 0, PATH_MAX);
@@ -60,7 +61,8 @@ int cmdlinepart_do_parse_one(const char *devname, const char *partstr,
 		if ((partition_flags & CMDLINEPART_ADD_DEVNAME) &&
 				strncmp(devname, partstr, strlen(devname)))
 			sprintf(buf, "%s.", devname);
-		memcpy(buf + strlen(buf), partstr, end - partstr);
+		partname_len = end - partstr;
+		memcpy(buf + strlen(buf), partstr, partname_len);
 
 		end++;
 	}
@@ -85,6 +87,11 @@ int cmdlinepart_do_parse_one(const char *devname, const char *partstr,
 
 	*retsize = size;
 
+	if (!partname_len) {
+		printf("partition name can't be empty\n");
+		return -EINVAL;
+	}
+
 	cdev = devfs_add_partition(devname, *offset, size, flags, buf);
 	if (IS_ERR(cdev)) {
 		printf("cannot create %s: %pe\n", buf, cdev);
-- 
2.39.5