Fix UB in index_map::insert

.github/workflows/build.yml

@@ -48,7 +48,16 @@ jobs:
           components: miri
 
       - name: Run miri
-        run: MIRIFLAGS=-Zmiri-ignore-leaks cargo miri test --features="alloc,defmt,mpmc_large,portable-atomic-critical-section,serde,ufmt,bytes,zeroize,embedded-io-v0.7"
+        run: >
+          MIRIFLAGS=-Zmiri-ignore-leaks cargo miri test --features="alloc,
+          defmt,
+          mpmc_large,
+          portable-atomic-critical-section,
+          serde,
+          ufmt,
+          bytes,
+          zeroize,
+          embedded-io-v0.7"
 
   # Run cargo test
   test:
@@ -84,7 +93,17 @@ jobs:
           toolchain: stable
 
       - name: Run cargo test
-        run: cargo test --features="alloc,defmt,mpmc_large,portable-atomic-critical-section,serde,ufmt,bytes,zeroize,embedded-io-v0.7"
+        run: >
+          cargo test --features="
+          alloc,
+          defmt,
+          mpmc_large,
+          portable-atomic-critical-section,
+          serde,
+          ufmt,
+          bytes,
+          zeroize,
+          embedded-io-v0.7"
 
   # Run cargo fmt --check
   style:
@@ -113,7 +132,15 @@ jobs:
         with:
           components: clippy
           targets: i686-unknown-linux-musl
-      - run: cargo clippy --all --target i686-unknown-linux-musl --all-targets
+      - run: >
+          cargo clippy --all --target i686-unknown-linux-musl --all-targets --features "alloc,
+            defmt,
+            portable-atomic-critical-section,
+            serde,
+            ufmt,
+            bytes,
+            zeroize,
+            embedded-io-v0.7"
 
   # Compilation check
   check:

CHANGELOG.md

@@ -13,6 +13,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Added `retain_back` (aka `truncate_front`) to `Deque`
 - Fixed unsoundness in `Vec::IntoIter::drop` and `HistoryBuf::write`in the context of panicking drop implementations.
 - Added `push_mut` to `Vec`.
+- Fixed unsoundness in `IndexMap:insert`.
+- Limited max size of `IndexMap` to u16::MAX + 1.
+  The implementation for sizes higher than u16::MAX were unsound anyway.
 
 ## [v0.9.3] 2025-04-15
 

src/de.rs

@@ -43,7 +43,7 @@ where
 
                 while let Some(value) = seq.next_element()? {
                     if values.push(value).is_err() {
-                        return Err(A::Error::invalid_length(values.capacity() + 1, &self))?;
+                        return Err(A::Error::invalid_length(values.capacity() + 1, &self));
                     }
                 }
 
@@ -84,7 +84,7 @@ where
 
                 while let Some(value) = seq.next_element()? {
                     if values.insert(value).is_err() {
-                        return Err(A::Error::invalid_length(values.capacity() + 1, &self))?;
+                        return Err(A::Error::invalid_length(values.capacity() + 1, &self));
                     }
                 }
 
@@ -124,7 +124,7 @@ where
 
                 while let Some(value) = seq.next_element()? {
                     if values.push(value).is_err() {
-                        return Err(A::Error::invalid_length(values.capacity() + 1, &self))?;
+                        return Err(A::Error::invalid_length(values.capacity() + 1, &self));
                     }
                 }
 
@@ -163,7 +163,7 @@ where
 
                 while let Some(value) = seq.next_element()? {
                     if values.push_back(value).is_err() {
-                        return Err(A::Error::invalid_length(values.capacity() + 1, &self))?;
+                        return Err(A::Error::invalid_length(values.capacity() + 1, &self));
                     }
                 }
 
@@ -245,7 +245,7 @@ where
 
                 while let Some((key, value)) = map.next_entry()? {
                     if values.insert(key, value).is_err() {
-                        return Err(A::Error::invalid_length(values.capacity() + 1, &self))?;
+                        return Err(A::Error::invalid_length(values.capacity() + 1, &self));
                     }
                 }
 
@@ -286,7 +286,7 @@ where
 
                 while let Some((key, value)) = map.next_entry()? {
                     if values.insert(key, value).is_err() {
-                        return Err(A::Error::invalid_length(values.capacity() + 1, &self))?;
+                        return Err(A::Error::invalid_length(values.capacity() + 1, &self));
                     }
                 }