numpy · ngoldbaum · Aug 6, 2025 · Jul 13, 2025 · Jul 13, 2025 · Jul 13, 2025
diff --git a/.github/workflows/compiler_sanitizers.yml b/.github/workflows/compiler_sanitizers.yml
@@ -21,7 +21,7 @@ permissions:
   contents: read # to fetch code (actions/checkout)
 
 jobs:
-  clang_ASAN:
+  clang_ASAN_UBSAN:
     # To enable this workflow on a fork, comment out:
     if: github.repository == 'numpy/numpy'
     runs-on: macos-latest
@@ -64,12 +64,14 @@ jobs:
         pip uninstall -y pytest-xdist
     - name: Build
       run:
-        python -m spin build -j2 -- -Db_sanitize=address
+        python -m spin build -- -Db_sanitize=address,undefined -Db_lundef=false
     - name: Test
       run: |
         # pass -s to pytest to see ASAN errors and warnings, otherwise pytest captures them
+        # Ignore test_casting_floatingpoint_errors on macOS for now - causes crash inside UBSAN
         ASAN_OPTIONS=detect_leaks=0:symbolize=1:strict_init_order=true:allocator_may_return_null=1 \
-        python -m spin test -- -v -s --timeout=600 --durations=10
+        UBSAN_OPTIONS=halt_on_error=1:suppressions=${GITHUB_WORKSPACE}/tools/ci/ubsan_suppressions_arm64.txt \
+        python -m spin test -- -k "not test_casting_floatingpoint_errors" -v -s --timeout=600 --durations=10
 
   clang_TSAN:
     # To enable this workflow on a fork, comment out:
@@ -78,9 +80,9 @@ jobs:
     container:
         image: ghcr.io/nascheme/numpy-tsan:3.14t
         options: --shm-size=2g # increase memory for large matrix ops
-      
+
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Trust working directory and initialize submodules
         run: |
           git config --global --add safe.directory /__w/numpy/numpy
@@ -98,3 +100,42 @@ jobs:
           python -m spin test \
           `find numpy -name "test*.py" | xargs grep -l "import threading" | tr '\n' ' '` \
            -- -v -s --timeout=600 --durations=10
+
+  ubuntu_UBSAN:
+    # To enable this workflow on a fork, comment out:
+    if: github.repository == 'numpy/numpy'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          submodules: recursive
+          fetch-tags: true
+          persist-credentials: false
+      - name: Set up pyenv
+        run: |
+          git clone https://github.com/pyenv/pyenv.git "$HOME/.pyenv"
+          PYENV_ROOT="$HOME/.pyenv"
+          PYENV_BIN="$PYENV_ROOT/bin"
+          PYENV_SHIMS="$PYENV_ROOT/shims"
+          echo "$PYENV_BIN" >> $GITHUB_PATH
+          echo "$PYENV_SHIMS" >> $GITHUB_PATH
+          echo "PYENV_ROOT=$PYENV_ROOT" >> $GITHUB_ENV
+      - name: Check pyenv is working
+        run: pyenv --version
+      - name: Build python with address sanitizer
+        run: |
+          CONFIGURE_OPTS="--with-address-sanitizer" pyenv install 3.14t
+          pyenv global 3.14t
+      - name: Install dependencies
+        run: |
+          pip install -r requirements/build_requirements.txt
+          pip install -r requirements/ci_requirements.txt
+          pip install -r requirements/test_requirements.txt
+      - name: Build numpy with UndefinedBehaviorSanitizer
+        run: python -m spin build -- -Db_sanitize=address,undefined -Db_lundef=false
+      - name: Test
+        run: |
+          # pass -s to pytest to see UBSAN errors and warnings, otherwise pytest captures them
+          ASAN_OPTIONS=detect_leaks=0:symbolize=1:strict_init_order=true:allocator_may_return_null=1 \
+          UBSAN_OPTIONS=halt_on_error=1:suppressions=${GITHUB_WORKSPACE}/tools/ci/ubsan_suppressions_x86_64.txt \
+          spin test -- -v -s --timeout=600 --durations=10
diff --git a/tools/ci/ubsan_suppressions_arm64.txt b/tools/ci/ubsan_suppressions_arm64.txt
@@ -0,0 +1,51 @@
+# This file contains suppressions for the default (with GIL) build to prevent runtime errors
+# when numpy is built with -Db_sanitize=undefined for arm64 architecture
+#
+# reference: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#available-checks
+
+# Per this prior discussion, integer overflow is not a concern
+# https://github.com/numpy/numpy/issues/24209#issuecomment-2160154181
+signed-integer-overflow:*
+
+# all alignment runtime errors ignored in favor of this being tracked via TypeSanitizer
+# otherwise ubsan may detect system file alignment errors outside numpy
+alignment:*
+
+# suggested fix for runtime error: use INT_MIN constant
+shift-base:_core/src/umath/_rational_tests.c
+# suggested fix for runtime error: check for overflow if signed
+shift-base:_core/src/npymath/npy_math_internal.h
+
+# suggested fix for runtime error: null check before loop
+pointer-overflow:_core/src/common/simd/neon/memory.h
+pointer-overflow:_core/src/multiarray/datetime_busdaycal.c
+pointer-overflow:_core/src/multiarray/nditer_templ.c
+pointer-overflow:_core/src/multiarray/nditer_constr.c
+pointer-overflow:_core/src/umath/loops_arithm_fp.dispatch.c.src
+pointer-overflow:_core/src/umath/loops_unary.dispatch.c.src
+pointer-overflow:_core/src/umath/loops_unary_complex.dispatch.c.src
+pointer-overflow:_core/src/umath/loops_unary_fp_le.dispatch.c.src
+pointer-overflow:_core/src/umath/string_buffer.h
+pointer-overflow:linalg/umath_linalg.cpp
+pointer-overflow:numpy/random/bit_generator.pyx.c
+
+float-cast-overflow:_core/src/multiarray/lowlevel_strided_loops.c.src
+
+# flagged in CI - call to function through pointer to incorrect function type
+# Many functions in the modules/files listed below cause undefined behavior in CI
+# general disable this check until further investigation, but keep the specific files
+# as a starting point for resolving the checks later
+function:_core/src/*
+function:numpy/random/*
+# function:_core/src/common/cblasfunc.c
+# function:_core/src/common/npy_argparse.c
+# function:_core/src/multiarray/number.c
+# function:_core/src/multiarray/ctors.c
+# function:_core/src/multiarray/convert_datatype.c
+# function:_core/src/multiarray/dtype_transfer.c
+# function:_core/src/multiarray/dtype_traversal.c
+# function:_core/src/multiarray/getset.c
+# function:_core/src/multiarray/scalarapi.c
+# function:_core/src/multiarray/scalartypes.c.src
+# function:_core/src/umath/*
+# function:numpy/random/*
diff --git a/tools/ci/ubsan_suppressions_x86_64.txt b/tools/ci/ubsan_suppressions_x86_64.txt
@@ -0,0 +1,31 @@
+# This file contains suppressions for the default (with GIL) build to prevent runtime errors
+# when numpy is built with -Db_sanitize=undefined for x86_64 architecture
+#
+# reference: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#available-checks
+
+# Per this prior discussion, integer overflow is not a concern
+# https://github.com/numpy/numpy/issues/24209#issuecomment-2160154181
+signed-integer-overflow:*
+
+# all alignment runtime errors ignored in favor of this being tracked via TypeSanitizer
+# otherwise ubsan may detect system file alignment errors outside numpy
+alignment:*
+
+# suggested fix for runtime error: replace left bit shift with LLONG_MIN constant
+shift-base:_core/src/common/simd/sse/arithmetic.h
+shift-base:_core/src/common/simd/avx2/arithmetic.h
+# suggested fix for runtime error: use INT_MIN constant
+shift-base:_core/src/umath/_rational_tests.c
+# suggested fix for runtime error: check for overflow if signed
+shift-base:_core/src/npymath/npy_math_internal.h
+
+
+# suggested fix for runtime error: check that pointer is not null before calling function
+nonnull-attribute:_core/src/multiarray/array_coercion.c
+nonnull-attribute:_core/src/multiarray/ctors.c
+nonnull-attribute:_core/src/multiarray/datetime_busdaycal.c
+nonnull-attribute:_core/src/multiarray/scalarapi.c
+nonnull-attribute:_core/src/multiarray/calculation.c
+
+# suggested fix for runtime error: null check before loop
+pointer-overflow:_core/src/multiarray/nditer_templ.c