cli/ota: Limit critical partition check to bootloader-verified partit…

…ions

dm-verity partitions don't necessarily have AVB descriptors inside the
root vbmeta images. The fstab might verify them against a public key on
disk using the `avb_keys` fs_mgr option. We have no way to statically
check for this scenario and it's becoming increasingly common on newer
OnePlus devices. Instead, we'll just limit the checks to partitions that
are verified by the bootloader.

Fixes: #223

Signed-off-by: Andrew Gunnerson <[email protected]>

avbroot/src/cli/ota.rs

@@ -271,20 +271,12 @@ fn load_vbmeta_images(
     Ok(result)
 }
 
-/// Check if a partition is critical to AVB's chain of trust. This is not
-/// foolproof and uses a heuristic based on AOSP's boot process. OEM-specific
-/// partitions may be equally important, but it's infeasible to list them all.
+/// Check if a partition is critical to AVB's chain of trust and is meant to be
+/// validated by the bootloader instead of Android. dm-verity partitions cannot
+/// be statically checked without causing false positives because the fstab
+/// might be using the avb_keys=/path/to/pubkey option.
 fn is_critical_to_avb(name: &str) -> bool {
-    name.ends_with("boot")
-        || name.ends_with("dlkm")
-        || name.starts_with("system")
-        || name.starts_with("vbmeta")
-        || name.starts_with("vendor")
-        || name == "dtbo"
-        || name == "odm"
-        || name == "product"
-        || name == "pvmfw"
-        || name == "recovery"
+    name.ends_with("boot") || name.starts_with("vbmeta")
 }
 
 /// Check that all critical partitions within the payload are protected by a