Drain remaining code-scanning alerts: idna pin, OSV ignores, FFI SAFETY + null-checks

crates/pecos-foreign/src/discovery.rs

@@ -157,6 +157,9 @@ pub fn load_plugin(path: &Path) -> Result<LoadedPlugin, PluginError> {
 
     // Wrap decoder if provided.
     let decoder = if !desc.decoder_handle.is_null() && !desc.decoder_vtable.is_null() {
+        // SAFETY: `decoder_vtable` was just null-checked; the plugin protocol
+        // requires `init_fn` to populate it with a `*const DecoderVTable` that
+        // points to a vtable owned by the loaded plugin for the plugin's lifetime.
         let vtable_copy = unsafe { *desc.decoder_vtable };
         unsafe { ForeignDecoder::new(desc.decoder_handle, vtable_copy) }
     } else {
@@ -165,6 +168,9 @@ pub fn load_plugin(path: &Path) -> Result<LoadedPlugin, PluginError> {
 
     // Wrap simulator if provided.
     let simulator = if !desc.simulator_handle.is_null() && !desc.simulator_vtable.is_null() {
+        // SAFETY: `simulator_vtable` was just null-checked; per plugin protocol,
+        // `init_fn` populates it with a `*const SimulatorVTable` owned by the
+        // loaded plugin for the plugin's lifetime.
         let vtable_copy = unsafe { *desc.simulator_vtable };
         unsafe {
             ForeignSimulator::new(

crates/pecos-foreign/src/engine.rs

@@ -153,7 +153,13 @@ pub unsafe extern "C" fn pecos_engine_process(
     output_ptr: *mut *mut u8,
     output_len: *mut usize,
 ) -> i32 {
+    if engine.is_null() {
+        return -1;
+    }
+    // SAFETY: null-checked above; per `# Safety` doc, no other reference exists
+    // for this call (single-threaded FFI contract), so `&mut` aliasing is unique.
     let eng = unsafe { &mut *engine };
+    // SAFETY: per `# Safety` doc, `input_ptr` is valid for `input_len` bytes.
     let input_bytes = unsafe { std::slice::from_raw_parts(input_ptr, input_len) };
     let input = ByteMessage::new(input_bytes);
 
@@ -185,6 +191,10 @@ pub unsafe extern "C" fn pecos_engine_process(
 /// `engine` must be a valid pointer from `pecos_engine_create`.
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn pecos_engine_reset(engine: *mut PecosEngine) -> i32 {
+    if engine.is_null() {
+        return -1;
+    }
+    // SAFETY: null-checked above; per `# Safety` doc, exclusively owned for this call.
     let eng = unsafe { &mut *engine };
     match eng.inner.reset() {
         Ok(()) => 0,
@@ -488,3 +498,30 @@ pub unsafe extern "C" fn pecos_free_outcomes(ptr: *mut u32, len: usize) {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn process_returns_minus_one_on_null_engine() {
+        let mut out_ptr: *mut u8 = std::ptr::null_mut();
+        let mut out_len: usize = 0;
+        let rc = unsafe {
+            pecos_engine_process(
+                std::ptr::null_mut(),
+                std::ptr::null(),
+                0,
+                &raw mut out_ptr,
+                &raw mut out_len,
+            )
+        };
+        assert_eq!(rc, -1);
+    }
+
+    #[test]
+    fn reset_returns_minus_one_on_null_engine() {
+        let rc = unsafe { pecos_engine_reset(std::ptr::null_mut()) };
+        assert_eq!(rc, -1);
+    }
+}

crates/pecos-qis-ffi/src/ffi.rs

@@ -1570,7 +1570,8 @@ mod tests {
         let ptr = unsafe { heap_alloc(100) };
         assert!(!ptr.is_null());
 
-        // Write to the memory to verify it's valid
+        // SAFETY: `ptr` was just allocated by `heap_alloc(100)` and asserted non-null
+        // above; the test scope owns it exclusively until `heap_free` below.
         unsafe {
             std::ptr::write(ptr, 42u8);
             assert_eq!(std::ptr::read(ptr), 42u8);

crates/pecos-qis-ffi/src/lib.rs

@@ -1048,7 +1048,8 @@ mod tests {
         let ptr = pecos_get_pending_operations();
         assert!(!ptr.is_null());
 
-        // Verify operations
+        // SAFETY: `pecos_get_pending_operations` returns a fresh leaked Box;
+        // non-null asserted above; the test scope owns it until `pecos_free_operations`.
         let collector = unsafe { &*ptr };
         assert_eq!(collector.operations.len(), 2);
 
@@ -1341,6 +1342,8 @@ mod tests {
         // Verify operations were exported
         let ops_ptr = pecos_get_pending_operations();
         assert!(!ops_ptr.is_null());
+        // SAFETY: `pecos_get_pending_operations` returns a fresh leaked Box;
+        // non-null asserted above; freed below via `pecos_free_operations`.
         let ops = unsafe { &*ops_ptr };
         assert_eq!(ops.operations.len(), 2);
         unsafe { pecos_free_operations(ops_ptr) };
@@ -1407,6 +1410,8 @@ mod tests {
         assert_eq!(needed_id, 0);
         let ops_ptr = pecos_get_pending_operations();
         assert!(!ops_ptr.is_null());
+        // SAFETY: `pecos_get_pending_operations` returns a fresh leaked Box;
+        // non-null asserted above; freed below via `pecos_free_operations`.
         let ops = unsafe { &*ops_ptr };
         assert_eq!(ops.operations, vec![Operation::AllocateQubit { id: 0 }]);
         unsafe { pecos_free_operations(ops_ptr) };
@@ -1416,6 +1421,8 @@ mod tests {
         assert_eq!(needed_id, 1);
         let ops_ptr = pecos_get_pending_operations();
         assert!(!ops_ptr.is_null());
+        // SAFETY: `pecos_get_pending_operations` returns a fresh leaked Box;
+        // non-null asserted above; freed below via `pecos_free_operations`.
         let ops = unsafe { &*ops_ptr };
         assert_eq!(ops.operations, vec![Operation::Quantum(QuantumOp::H(0))]);
         unsafe { pecos_free_operations(ops_ptr) };

docs/requirements.txt

@@ -4,3 +4,4 @@ mkdocstrings>=0.24.0
 mkdocstrings-python>=1.7.4
 markdown-exec>=1.10.3
 pymdown-extensions>=10.21.3
+idna>=3.15  # CVE-2026-45409 (re-fix of CVE-2024-3651): idna.encode() DoS on crafted long inputs

osv-scanner.toml

@@ -0,0 +1,67 @@
+# OSV-Scanner configuration for the PECOS workspace.
+#
+# Ignore list policy:
+# - Only include entries we cannot fix from this repo (transitive, blocked on
+#   an upstream release).
+# - Each entry must record (a) the offending crate@version, (b) the chain that
+#   pulls it in, and (c) the upstream that owns the fix.
+# - Real CVEs on first-party deps are NEVER ignored here -- pin and fix them
+#   in the manifest instead (see docs/requirements.txt for the idna pin).
+# - Periodically review this list when bumping hugr/tket, fusion-blossom, or
+#   mwpf and drop entries that the new upstream version eliminates.
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2025-0057"
+# fxhash@0.2.1 -- unmaintained.
+# Chain: hugr-passes -> hugr -> tket -> pecos-hugr.
+# Upstream owner: https://github.com/CQCL/hugr (awaiting rustc-hash/ahash swap).
+reason = "Transitive via hugr/tket; unmaintained-crate warning, no exploit path in PECOS."
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2024-0436"
+# paste@1.0.15 -- unmaintained proc-macro.
+# Chain: hugr-passes/ascent and mwpf both pull it in.
+# Upstream owners: https://github.com/CQCL/hugr and https://github.com/yuewuo/mwpf.
+reason = "Transitive via hugr/tket and mwpf; unmaintained-crate warning, no runtime impact (proc-macro)."
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2024-0388"
+# derivative@2.2.0 -- unmaintained proc-macro.
+# Chain: fusion-blossom and mwpf both pull it in.
+# Upstream owners: https://github.com/yuewuo/fusion-blossom and https://github.com/yuewuo/mwpf.
+reason = "Transitive via fusion-blossom and mwpf; unmaintained-crate warning, no runtime impact (proc-macro)."
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2024-0384"
+# instant@0.1.13 -- unmaintained; replaced by web-time.
+# Chain: hugr-passes/ascent -> ... -> pecos-hugr.
+# Upstream owner: https://github.com/CQCL/hugr (ascent is a transitive build-graph helper).
+reason = "Transitive via hugr-passes/ascent; unmaintained-crate warning, no Wasm target."
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2024-0375"
+# atty@0.2.14 -- unmaintained (clap 4.x dropped it).
+# Chain: mwpf -> slp -> structopt 0.3 -> clap 2.34.
+# Upstream owner: https://github.com/yuewuo/mwpf (awaiting clap 4 / pico-args migration in slp).
+reason = "Transitive via mwpf -> slp (clap2-era CLI helper); CLI tty-detect path not exercised by PECOS."
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2024-0370"
+# proc-macro-error@1.0.4 -- unmaintained; proc-macro-error2 is the maintained fork.
+# Chain: mwpf -> slp -> structopt-derive (compile-time only).
+# Upstream owner: https://github.com/yuewuo/mwpf.
+reason = "Transitive via mwpf -> slp -> structopt-derive; compile-time proc-macro only, no runtime impact."
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2021-0145"
+# atty@0.2.14 -- potential unaligned read on Windows custom allocators.
+# Chain: mwpf -> slp -> structopt 0.3 -> clap 2.34.
+# Upstream owner: https://github.com/yuewuo/mwpf.
+reason = "Transitive via mwpf -> slp -> clap2; PECOS does not invoke slp's CLI tty-detection at runtime."
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2021-0139"
+# ansi_term@0.12.1 -- unmaintained.
+# Chain: mwpf -> slp -> structopt 0.3 -> clap 2.34.
+# Upstream owner: https://github.com/yuewuo/mwpf.
+reason = "Transitive via mwpf -> slp -> clap2; unmaintained-crate warning, terminal-color path unused."

python/quantum-pecos/docs/requirements.txt

@@ -1,5 +1,6 @@
 matplotlib==3.9.2
-pillow>=11.3.0  # security floor: Pillow is transitive via matplotlib; avoid known-vulnerable old releases
+pillow>=11.3.0  # CVE-2023-50447 + libwebp; transitive via matplotlib
+idna>=3.15  # CVE-2026-45409 (re-fix of CVE-2024-3651): idna.encode() DoS on crafted long inputs
 networkx==3.3
 numpy==1.26.4
 scipy==1.14.1

scripts/native_bench/bench_pecos/osv-scanner.toml

@@ -0,0 +1,8 @@
+# OSV-Scanner configuration for the native_bench/bench_pecos workspace.
+# See root osv-scanner.toml for policy.
+
+[[IgnoredVulns]]
+id = "RUSTSEC-2024-0436"
+# paste@1.0.15 -- unmaintained proc-macro; same chain as workspace root.
+# Upstream owner: https://github.com/CQCL/hugr and https://github.com/yuewuo/mwpf.
+reason = "Transitive via bench dependencies; unmaintained-crate warning, no runtime impact (proc-macro)."