[PATCH v9 2/6] luks2: Do not handle disks of size GRUB_DISK_SIZE_UNKNOWN for now

[Glenn Washburn]

Check to make sure that source disk has a known size. If not, print debug
message and return error. There are 4 cases where GRUB_DISK_SIZE_UNKNOWN is
set (biosdisk, obdisk, ofdisk, and uboot), and in all those cases processing
continues. So this is probably a bit conservative. However, 3 of the cases
seem pathological, and the other, biosdisk, happens when booting from a cd.
Since I doubt booting from a LUKS2 volume on a cd is a big use case, we'll
error until someone complains.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/disk/luks2.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
index 8c1156dd0..d30c3bfff 100644
--- a/grub-core/disk/luks2.c
+++ b/grub-core/disk/luks2.c
@@ -600,6 +600,15 @@ luks2_recover_key (grub_disk_t source,
       goto err;
     }
 
+  if (grub_disk_native_sectors(source) == GRUB_DISK_SIZE_UNKNOWN)
+    {
+      /* FIXME: Allow use of source disk, and maybe cause errors in read. */
+      grub_dprintf ("luks2", "Source disk %s has an unknown size, "
+                            "conservatively returning error\n", source->name);
+      ret = grub_error (GRUB_ERR_BUG, "Unknown size of luks2 source device");
+      goto err;
+    }
+
   /* Try all keyslot */
   for (json_idx = 0; json_idx < size; json_idx++)
     {
-- 
2.27.0