core: fix loading verity settings for MountImages= (#35577)

The MountEntry logic was refactored to store the verity
settings, and updated for ExtensionImages=, but not for
MountImages=.

Follow-up for a1a40297db

test/units/TEST-50-DISSECT.dissect.sh

@@ -281,6 +281,9 @@ systemd-run -P \
             -p RootHash="$MINIMAL_IMAGE_ROOTHASH" \
             -p MountImages="$MINIMAL_IMAGE.gpt:/run/img1 $MINIMAL_IMAGE.raw:/run/img2" \
             cat /run/img2/usr/lib/os-release | grep -q -F "MARKER=1"
+systemd-run -P \
+            -p MountImages="$MINIMAL_IMAGE.raw:/run/img2" \
+            veritysetup status "${MINIMAL_IMAGE_ROOTHASH}-verity" | grep -q "${MINIMAL_IMAGE_ROOTHASH}"
 cat >/run/systemd/system/testservice-50c.service <<EOF
 [Service]
 MountAPIVFS=yes
@@ -362,6 +365,12 @@ systemd-run -P \
             --property ExtensionImages=/etc/service-scoped-test.raw \
             --property RootImage="$MINIMAL_IMAGE.raw" \
             cat /etc/systemd/system/some_file | grep -q -F "MARKER_CONFEXT_123"
+systemd-run -P \
+            --property ExtensionImages="/tmp/app0.raw /tmp/conf0.raw" \
+            veritysetup status "$(cat /tmp/app0.roothash)-verity" | grep -q "$(cat /tmp/app0.roothash)"
+systemd-run -P \
+            --property ExtensionImages="/tmp/app0.raw /tmp/conf0.raw" \
+            veritysetup status "$(cat /tmp/conf0.roothash)-verity" | grep -q "$(cat /tmp/conf0.roothash)"
 
 # Check that two identical verity images at different paths do not fail with -ELOOP from OverlayFS
 mkdir -p /tmp/loop

test/units/util.sh

@@ -284,6 +284,7 @@ EOF
         chmod +x "$initdir/opt/script0.sh"
         echo MARKER=1 >"$initdir/usr/lib/systemd/system/some_file"
         mksquashfs "$initdir" /tmp/app0.raw -noappend
+        veritysetup format /tmp/app0.raw /tmp/app0.verity --root-hash-file /tmp/app0.roothash
 
         initdir="/var/tmp/conf0"
         mkdir -p "$initdir/etc/extension-release.d" "$initdir/etc/systemd/system" "$initdir/opt"
@@ -295,6 +296,7 @@ EOF
         ) >>"$initdir/etc/extension-release.d/extension-release.conf0"
         echo MARKER_1 >"$initdir/etc/systemd/system/some_file"
         mksquashfs "$initdir" /tmp/conf0.raw -noappend
+        veritysetup format /tmp/conf0.raw /tmp/conf0.verity --root-hash-file /tmp/conf0.roothash
 
         initdir="/var/tmp/app1"
         mkdir -p "$initdir/usr/lib/extension-release.d" "$initdir/usr/lib/systemd/system" "$initdir/opt"