From 41629720392930a7c784a67f1818df7e341da230 Mon Sep 17 00:00:00 2001
From: "prompt.ac/@jeffrey" <mail@aesthetic.computer>
Date: Sat, 5 Sep 2026 14:41:35 -0400
Subject: [PATCH] Harden Mediascholar sandbox on Ubuntu

---
 papers/mediascholar/apparmor/mediascholar-bwrap | 10 ++++++++++
 papers/mediascholar/install-jasellite.sh        | 14 ++++++++++++--
 papers/mediascholar/run-sandboxed.sh            |  8 +++++++-
 3 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 papers/mediascholar/apparmor/mediascholar-bwrap

diff --git a/papers/mediascholar/apparmor/mediascholar-bwrap b/papers/mediascholar/apparmor/mediascholar-bwrap
new file mode 100644
index 0000000000..d6cf9f7aae
--- /dev/null
+++ b/papers/mediascholar/apparmor/mediascholar-bwrap
@@ -0,0 +1,10 @@
+# Permit Bubblewrap to create the user namespace used by Mediascholar without
+# relaxing Ubuntu's global restriction on unprivileged user namespaces.
+abi <abi/4.0>,
+include <tunables/global>
+
+profile mediascholar-bwrap flags=(unconfined) {
+  userns,
+
+  include if exists <local/mediascholar-bwrap>
+}
diff --git a/papers/mediascholar/install-jasellite.sh b/papers/mediascholar/install-jasellite.sh
index 42b3393fec..38017e4c64 100644
--- a/papers/mediascholar/install-jasellite.sh
+++ b/papers/mediascholar/install-jasellite.sh
@@ -20,7 +20,8 @@ RUNNER="$SOURCE_RUNNER"
 stage_runtime() {
   [[ -d "$REPO/node_modules" ]] || { echo "$REPO/node_modules is required" >&2; exit 1; }
   install -d -m 0755 \
-    "$RUNTIME/papers/bin" "$RUNTIME/papers/mediascholar/systemd" \
+    "$RUNTIME/papers/bin" "$RUNTIME/papers/mediascholar/apparmor" \
+    "$RUNTIME/papers/mediascholar/systemd" \
     "$RUNTIME/slab/bin" "$RUNTIME/toolchain/mcp"
   install -m 0755 "$SOURCE_ROOT/papers/bin/mediascholar.mjs" "$RUNTIME/papers/bin/mediascholar.mjs"
   install -m 0755 "$SOURCE_ROOT/papers/mediascholar/run-sandboxed.sh" "$RUNTIME/papers/mediascholar/run-sandboxed.sh"
@@ -37,6 +38,8 @@ stage_runtime() {
     "$SOURCE_ROOT/papers/mediascholar/topic-prompt.md" \
     "$SOURCE_ROOT/papers/mediascholar/paper-prompt.md" \
     "$RUNTIME/papers/mediascholar/"
+  install -m 0644 "$SOURCE_ROOT/papers/mediascholar/apparmor/mediascholar-bwrap" \
+    "$RUNTIME/papers/mediascholar/apparmor/mediascholar-bwrap"
   install -m 0755 "$SOURCE_ROOT/papers/mediascholar/install-jasellite.sh" \
     "$RUNTIME/papers/mediascholar/install-jasellite.sh"
   install -m 0644 "$SOURCE"/*.service "$SOURCE"/*.timer "$RUNTIME/papers/mediascholar/systemd/"
@@ -89,7 +92,14 @@ install_dependencies() {
   sudo -n ionice -c 3 nice -n 19 apt-get update
   sudo -n ionice -c 3 nice -n 19 apt-get install -y --no-install-recommends \
     texlive-xetex texlive-latex-extra texlive-fonts-recommended texlive-bibtex-extra \
-    poppler-utils imagemagick zip bubblewrap
+    poppler-utils imagemagick zip bubblewrap apparmor-utils
+  if command -v aa-exec >/dev/null 2>&1 && \
+     [[ -w /sys/kernel/security/apparmor/.load || -e /sys/module/apparmor ]]; then
+    sudo -n install -m 0644 \
+      "$RUNTIME/papers/mediascholar/apparmor/mediascholar-bwrap" \
+      /etc/apparmor.d/mediascholar-bwrap
+    sudo -n apparmor_parser -r /etc/apparmor.d/mediascholar-bwrap
+  fi
 }
 
 install_codex() {
diff --git a/papers/mediascholar/run-sandboxed.sh b/papers/mediascholar/run-sandboxed.sh
index f9bc5b0507..f47ed88132 100644
--- a/papers/mediascholar/run-sandboxed.sh
+++ b/papers/mediascholar/run-sandboxed.sh
@@ -19,6 +19,12 @@ fi
 
 mkdir -p "$STATE" "$ADVERTISE_DIR"
 
+declare -a bwrap_command=(bwrap)
+if command -v aa-exec >/dev/null 2>&1 && \
+   aa-exec -p mediascholar-bwrap -- /bin/true >/dev/null 2>&1; then
+  bwrap_command=(aa-exec -p mediascholar-bwrap -- bwrap)
+fi
+
 declare -a root_paths=()
 for source_path in /bin /sbin /lib /lib64; do
   if [[ -L "$source_path" ]]; then
@@ -28,7 +34,7 @@ for source_path in /bin /sbin /lib /lib64; do
   fi
 done
 
-exec bwrap \
+exec "${bwrap_command[@]}" \
   --die-with-parent \
   --new-session \
   --unshare-pid \
-- 
2.51.2