docs: add implementation plan for audit bug fixes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/superpowers/plans/2026-03-26-audit-bugfixes.md

@@ -0,0 +1,521 @@
+# Audit Bug Fixes — Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Fix 9 bugs (3 P0, 6 P1) identified by the 5-agent code audit.
+
+**Architecture:** Independent, targeted fixes across backend and frontend. No architectural changes. Each task is self-contained and can be committed independently.
+
+**Tech Stack:** Rust (Axum, tokio), SolidJS, TypeScript
+
+**Spec:** `docs/superpowers/specs/2026-03-26-audit-bugfixes-design.md`
+
+---
+
+### Task 1: Fix UTF-8 panic in error sanitization
+
+**Files:**
+- Modify: `backend/src/services/synthesis.rs`
+
+- [ ] **Step 1: Find and fix the unsafe slice**
+
+In `backend/src/services/synthesis.rs`, find the `sanitize_error_message` function (around line 1305). Replace:
+
+```rust
+if msg.len() > 200 {
+    format!("{}...", &msg[..200])
+}
+```
+
+With:
+
+```rust
+if msg.len() > 200 {
+    let truncated: String = msg.chars().take(200).collect();
+    format!("{}...", truncated)
+}
+```
+
+- [ ] **Step 2: Add a test**
+
+Add a test in the same file's `#[cfg(test)] mod tests` block:
+
+```rust
+#[test]
+fn sanitize_error_message_handles_multibyte_utf8() {
+    // This would panic with &msg[..200] if the 200th byte falls mid-character
+    let msg = "é".repeat(150); // 300 bytes, 150 chars
+    let result = sanitize_error_message(&msg);
+    assert!(result.len() <= 600); // 200 chars * 2 bytes each + "..."
+    assert!(result.ends_with("..."));
+}
+```
+
+Note: `sanitize_error_message` may be private. If so, test via a helper or make `pub(crate)` for testing.
+
+- [ ] **Step 3: Run tests**
+
+Run: `cd backend && cargo test --lib`
+Expected: All pass
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add backend/src/services/synthesis.rs
+git commit -m "fix: prevent UTF-8 panic in error message truncation"
+```
+
+---
+
+### Task 2: Fix job creation race condition + pipeline timeout + panic handling
+
+**Files:**
+- Modify: `backend/src/services/synthesis.rs`
+- Modify: `backend/src/handlers/generation.rs`
+
+These three bugs (race condition, no timeout, swallowed panics) all touch the job lifecycle in `synthesis.rs` and the spawn in `generation.rs`. They must be applied together to avoid a window where panics permanently lock out users.
+
+- [ ] **Step 1: Add `generating_users` DashSet to JobStore in `synthesis.rs`**
+
+Add `use dashmap::DashSet;` to imports. Update `JobStore`:
+
+```rust
+pub struct JobStore {
+    inner: Arc<DashMap<Uuid, JobEntry>>,
+    generating_users: Arc<DashSet<Uuid>>,
+}
+```
+
+Update `new()`:
+```rust
+pub fn new() -> Self {
+    Self {
+        inner: Arc::new(DashMap::new()),
+        generating_users: Arc::new(DashSet::new()),
+    }
+}
+```
+
+- [ ] **Step 2: Update `create_job`, `has_active_job`, `cleanup_expired`, add `release_user`**
+
+Replace `create_job`:
+```rust
+pub fn create_job(&self, user_id: Uuid) -> Option<(Uuid, Arc<watch::Sender<ProgressEvent>>)> {
+    if !self.generating_users.insert(user_id) {
+        return None;
+    }
+    let job_id = Uuid::new_v4();
+    let (tx, rx) = watch::channel(ProgressEvent::Progress {
+        step: "init".into(), message: "Initialisation...".into(), percent: 0,
+    });
+    let tx = Arc::new(tx);
+    self.inner.insert(job_id, JobEntry {
+        tx: Arc::clone(&tx), _rx: rx, user_id, created_at: Instant::now(),
+    });
+    Some((job_id, tx))
+}
+```
+
+Simplify `has_active_job`:
+```rust
+pub fn has_active_job(&self, user_id: Uuid) -> Option<Uuid> {
+    if !self.generating_users.contains(&user_id) { return None; }
+    for entry in self.inner.iter() {
+        if entry.value().user_id == user_id { return Some(*entry.key()); }
+    }
+    None
+}
+```
+
+Add `release_user`:
+```rust
+pub fn release_user(&self, user_id: Uuid) {
+    self.generating_users.remove(&user_id);
+}
+```
+
+Update `cleanup_expired`:
+```rust
+pub fn cleanup_expired(&self) {
+    let now = Instant::now();
+    self.inner.retain(|_, entry| {
+        let keep = now.duration_since(entry.created_at) < JOB_TTL;
+        if !keep { self.generating_users.remove(&entry.user_id); }
+        keep
+    });
+}
+```
+
+- [ ] **Step 3: Update the spawn in `generation.rs` — timeout + panic handling + release**
+
+In `backend/src/handlers/generation.rs`, find the spawn block (around line 70-75). Replace it with:
+
+```rust
+// Clone tx before moving into spawn so we can use it for panic handling
+let tx_for_panic = Arc::clone(&tx);
+let state_for_panic = state.clone();
+
+let join_handle = tokio::spawn(async move {
+    let timeout_duration = std::time::Duration::from_secs(900); // 15 minutes
+    match tokio::time::timeout(timeout_duration, synthesis::run_generation(job_id, state_clone.clone(), user_id, tx.clone())).await {
+        Ok(()) => {}
+        Err(_) => {
+            tracing::error!(job_id = %job_id, user_id = %user_id, "Generation timed out after 15 minutes");
+            let _ = tx.send(synthesis::ProgressEvent::Error {
+                message: "La generation a depasse le delai maximum de 15 minutes.".into(),
+            });
+        }
+    }
+    state_clone.job_store.release_user(user_id);
+});
+
+// Monitor for panics — if the task panics, release_user inside won't run
+tokio::spawn(async move {
+    if let Err(e) = join_handle.await {
+        tracing::error!(job_id = %job_id, error = %e, "Generation task panicked");
+        let _ = tx_for_panic.send(synthesis::ProgressEvent::Error {
+            message: "Erreur interne lors de la generation.".into(),
+        });
+        state_for_panic.job_store.release_user(user_id);
+    }
+});
+```
+
+Read the file first to get the exact variable names (`state_clone`, `tx`, `job_id`, `user_id`).
+
+- [ ] **Step 4: Build and test**
+
+Run: `cd backend && cargo build && cargo test --lib`
+Expected: All pass
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add backend/src/services/synthesis.rs backend/src/handlers/generation.rs
+git commit -m "fix: atomic job creation, 15min timeout, and panic handling"
+```
+
+---
+
+### Task 3: Fix XSS via innerHTML + setTimeout cleanup in GenerateSynthesis.tsx
+
+**Files:**
+- Modify: `frontend/src/pages/GenerateSynthesis.tsx`
+
+- [ ] **Step 1: Replace innerHTML with safe text**
+
+Find the `innerHTML` usage (around line 249):
+
+```tsx
+<p innerHTML={t('generate.description', {
+  days: String(settings().max_age_days),
+  theme: settings().theme,
+})} />
+```
+
+Replace with:
+
+```tsx
+<p class="text-gray-600">
+  {t('generate.description', {
+    days: String(settings().max_age_days),
+    theme: settings().theme,
+  })}
+</p>
+```
+
+- [ ] **Step 2: Add onCleanup for setTimeout**
+
+Find the `setTimeout` (around line 187):
+
+```tsx
+setTimeout(() => {
+  navigate(`/synthesis/${synthId}`);
+}, 2000);
+```
+
+Replace with:
+
+```tsx
+const timer = setTimeout(() => {
+  navigate(`/synthesis/${synthId}`);
+}, 2000);
+onCleanup(() => clearTimeout(timer));
+```
+
+Make sure `onCleanup` is imported from `solid-js` at the top of the file.
+
+- [ ] **Step 3: TypeScript check**
+
+Run: `cd frontend && npx tsc --noEmit`
+Expected: No errors
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add frontend/src/pages/GenerateSynthesis.tsx
+git commit -m "fix: remove XSS via innerHTML and add setTimeout cleanup"
+```
+
+---
+
+### Task 4: Add expired session cleanup background task
+
+**Files:**
+- Modify: `backend/src/main.rs`
+
+- [ ] **Step 1: Add periodic session cleanup**
+
+In `backend/src/main.rs`, find the `Commands::Serve` block. After the rate limiter reload and before `let app = router::build_router(...)`, spawn a background task:
+
+```rust
+// Periodic session cleanup (every hour)
+{
+    let cleanup_pool = state.pool.clone();
+    tokio::spawn(async move {
+        let mut interval = tokio::time::interval(std::time::Duration::from_secs(3600));
+        loop {
+            interval.tick().await;
+            match crate::db::sessions::delete_expired(&cleanup_pool).await {
+                Ok(count) => {
+                    if count > 0 {
+                        tracing::info!(deleted = count, "Cleaned up expired sessions");
+                    }
+                }
+                Err(e) => {
+                    tracing::warn!(error = %e, "Failed to clean up expired sessions");
+                }
+            }
+        }
+    });
+}
+```
+
+- [ ] **Step 2: Build and test**
+
+Run: `cd backend && cargo build && cargo test --lib`
+Expected: All pass
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add backend/src/main.rs
+git commit -m "fix: add periodic expired session cleanup (hourly)"
+```
+
+---
+
+### Task 5: Fix SSRF bypass via IPv4-mapped IPv6
+
+**Files:**
+- Modify: `backend/src/services/scraper.rs`
+
+- [ ] **Step 1: Add IPv4-mapped check to `is_private_ip`**
+
+In `backend/src/services/scraper.rs`, find the `is_private_ip` function (around line 294). Add a check at the beginning of the `IpAddr::V6` branch:
+
+```rust
+IpAddr::V6(v6) => {
+    // Check for IPv4-mapped IPv6 addresses (::ffff:x.x.x.x)
+    if let Some(mapped_v4) = v6.to_ipv4_mapped() {
+        return mapped_v4.is_loopback()
+            || mapped_v4.is_private()
+            || mapped_v4.is_link_local()
+            || mapped_v4.is_unspecified();
+    }
+
+    let segments = v6.segments();
+    v6.is_loopback()
+    // ... rest of existing checks
+```
+
+- [ ] **Step 2: Add tests for IPv4-mapped addresses**
+
+Find the SSRF tests section and add:
+
+```rust
+#[test]
+fn rejects_ipv4_mapped_ipv6_loopback() {
+    let ip: IpAddr = "::ffff:127.0.0.1".parse().unwrap();
+    assert!(is_private_ip(ip));
+}
+
+#[test]
+fn rejects_ipv4_mapped_ipv6_private_10() {
+    let ip: IpAddr = "::ffff:10.0.0.1".parse().unwrap();
+    assert!(is_private_ip(ip));
+}
+
+#[test]
+fn rejects_ipv4_mapped_ipv6_private_192() {
+    let ip: IpAddr = "::ffff:192.168.1.1".parse().unwrap();
+    assert!(is_private_ip(ip));
+}
+
+#[test]
+fn rejects_ipv4_mapped_ipv6_link_local() {
+    let ip: IpAddr = "::ffff:169.254.1.1".parse().unwrap();
+    assert!(is_private_ip(ip));
+}
+
+#[test]
+fn allows_ipv4_mapped_ipv6_public() {
+    let ip: IpAddr = "::ffff:8.8.8.8".parse().unwrap();
+    assert!(!is_private_ip(ip));
+}
+```
+
+- [ ] **Step 3: Run tests**
+
+Run: `cd backend && cargo test --lib scraper`
+Expected: All pass including the 5 new tests
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add backend/src/services/scraper.rs
+git commit -m "fix: block SSRF via IPv4-mapped IPv6 addresses"
+```
+
+---
+
+### Task 6: Add SSRF check to source page fetching
+
+**Files:**
+- Modify: `backend/src/services/source_scraper.rs`
+- Modify: `backend/src/services/scraper.rs` (make `check_ssrf` public)
+
+- [ ] **Step 1: Make `check_ssrf` public**
+
+In `backend/src/services/scraper.rs`, find `async fn check_ssrf` (around line 240) and change to:
+
+```rust
+pub async fn check_ssrf(url: &url::Url) -> Result<(), AppError> {
+```
+
+- [ ] **Step 2: Add SSRF check in `extract_article_links`**
+
+In `backend/src/services/source_scraper.rs`, find `extract_article_links` (around line 32). Add the SSRF check before the HTTP fetch:
+
+```rust
+pub async fn extract_article_links(
+    http_client: &reqwest::Client,
+    source_url: &str,
+    max_links: usize,
+) -> Result<Vec<String>, AppError> {
+    let base_url = Url::parse(source_url)
+        .map_err(|e| AppError::BadRequest(format!("Invalid source URL: {}", e)))?;
+
+    // SSRF check before fetching
+    if let Err(e) = crate::services::scraper::check_ssrf(&base_url).await {
+        tracing::warn!(url = source_url, error = %e, "Source URL failed SSRF check");
+        return Ok(Vec::new());
+    }
+
+    let base_domain = base_url.host_str().unwrap_or("").to_lowercase();
+    // ... rest unchanged
+```
+
+- [ ] **Step 3: Add SSRF check in `extract_article_links_with_llm`**
+
+Same pattern in `extract_article_links_with_llm` (around line 185), add after `base_url` parse:
+
+```rust
+    // SSRF check before fetching
+    if let Err(e) = crate::services::scraper::check_ssrf(&base_url).await {
+        tracing::warn!(url = source_url, error = %e, "Source URL failed SSRF check");
+        return Ok(Vec::new());
+    }
+```
+
+- [ ] **Step 4: Build and test**
+
+Run: `cd backend && cargo build && cargo test --lib`
+Expected: All pass
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add backend/src/services/scraper.rs backend/src/services/source_scraper.rs
+git commit -m "fix: add SSRF check before fetching source pages"
+```
+
+---
+
+### Task 7: Add onCleanup for setTimeout in frontend pages
+
+**Files:**
+- Modify: `frontend/src/pages/Home.tsx`
+- Modify: `frontend/src/pages/ArticleHistory.tsx`
+- Modify: `frontend/src/pages/SynthesisDetail.tsx`
+
+- [ ] **Step 1: Fix Home.tsx**
+
+In `frontend/src/pages/Home.tsx`, add `onCleanup` to the `solid-js` import. Add cleanup for the delete confirmation timers at the component level:
+
+```tsx
+onCleanup(() => {
+  const timers = deleteTimers();
+  Object.values(timers).forEach((timer) => clearTimeout(timer));
+});
+```
+
+- [ ] **Step 2: Fix ArticleHistory.tsx**
+
+In `frontend/src/pages/ArticleHistory.tsx`, add `onCleanup` and `createSignal` to the `solid-js` import (if not already present). Use a signal to track the timer:
+
+```tsx
+const [confirmTimer, setConfirmTimer] = createSignal<ReturnType<typeof setTimeout> | undefined>();
+
+// At component top level:
+onCleanup(() => {
+  const t = confirmTimer();
+  if (t) clearTimeout(t);
+});
+```
+
+Then in the `handleClear` function, replace:
+```tsx
+setTimeout(() => setConfirming(false), 3000);
+```
+with:
+```tsx
+setConfirmTimer(setTimeout(() => setConfirming(false), 3000));
+```
+
+- [ ] **Step 3: Fix SynthesisDetail.tsx**
+
+In `frontend/src/pages/SynthesisDetail.tsx`, add `onCleanup` and `createSignal` to the `solid-js` import. The `setTimeout` is inside the async `sendEmail` handler, so use a signal to track it (same pattern as ArticleHistory):
+
+```tsx
+const [emailTimer, setEmailTimer] = createSignal<ReturnType<typeof setTimeout> | undefined>();
+
+// At component top level:
+onCleanup(() => {
+  const t = emailTimer();
+  if (t) clearTimeout(t);
+});
+```
+
+Then replace:
+```tsx
+setTimeout(() => setEmailSuccess(false), 5000);
+```
+with:
+```tsx
+setEmailTimer(setTimeout(() => setEmailSuccess(false), 5000));
+```
+
+Read the file first to find ALL `setTimeout` calls and apply the same pattern to each.
+
+- [ ] **Step 4: TypeScript check**
+
+Run: `cd frontend && npx tsc --noEmit`
+Expected: No errors
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add frontend/src/pages/Home.tsx frontend/src/pages/ArticleHistory.tsx frontend/src/pages/SynthesisDetail.tsx
+git commit -m "fix: add onCleanup for setTimeout in frontend pages"
+```