[PATCH 09/10] Fix efi_bind_block.

[Matthew Garrett <mjg59@srcf.ucam.org>]

From: Janis Danisevskis <jdanisevskis@aurora.tech>

efi_bind_block had two issues.
1. A pointer to a the stack was inserted as plat structure and thus used
beyond its life time.
2. Only the first segment of the device path was copied into the
platfom data structure resulting in an unterminated device path.

Signed-off-by: Janis Danisevskis <jdanisevskis@aurora.tech>
Signed-off-by: Matthew Garrett <mgarrett@aurora.tech>
---

 lib/efi/efi_app_init.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/lib/efi/efi_app_init.c b/lib/efi/efi_app_init.c
index 9704020b749..cc91e1d74b8 100644
--- a/lib/efi/efi_app_init.c
+++ b/lib/efi/efi_app_init.c
@@ -19,6 +19,15 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+static size_t device_path_length(const struct efi_device_path *device_path)
+{
+	const struct efi_device_path *d;
+
+	for (d = device_path; d->type != DEVICE_PATH_TYPE_END; d = (void *)d + d->length) {
+	}
+	return (void *)d - (void *)device_path + d->length;
+}
+
 /**
  * efi_bind_block() - bind a new block device to an EFI device
  *
@@ -39,19 +48,23 @@ int efi_bind_block(efi_handle_t handle, struct efi_block_io *blkio,
 		   struct efi_device_path *device_path, int len,
 		   struct udevice **devp)
 {
-	struct efi_media_plat plat;
+	struct efi_media_plat *plat;
 	struct udevice *dev;
 	char name[18];
 	int ret;
-
-	plat.handle = handle;
-	plat.blkio = blkio;
-	plat.device_path = malloc(device_path->length);
-	if (!plat.device_path)
+	size_t device_path_len = device_path_length(device_path);
+
+	plat = malloc(sizeof(struct efi_media_plat));
+	if (!plat)
+		return log_msg_ret("plat", -ENOMEM);
+	plat->handle = handle;
+	plat->blkio = blkio;
+	plat->device_path = malloc(device_path_len);
+	if (!plat->device_path)
 		return log_msg_ret("path", -ENOMEM);
-	memcpy(plat.device_path, device_path, device_path->length);
+	memcpy(plat->device_path, device_path, device_path_len);
 	ret = device_bind(dm_root(), DM_DRIVER_GET(efi_media), "efi_media",
-			  &plat, ofnode_null(), &dev);
+			  plat, ofnode_null(), &dev);
 	if (ret)
 		return log_msg_ret("bind", ret);
 
-- 
2.47.0