https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97294
Bug ID: 97294 Summary: ASAN "dynamic-stack-buffer-overflow" false positive with OpenMP reduction to std::vector Product: gcc Version: 10.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: sanitizer Assignee: unassigned at gcc dot gnu.org Reporter: paulg-b at web dot de CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org, jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at gcc dot gnu.org Target Milestone: --- Created attachment 49308 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49308&action=edit Minimal example When the attached minimal example is compiled with g++ -fsanitize=address -fopenmp -o asan_omp_test asan_omp_test.cpp and executed, ASAN reports a dynamic-stack-buffer-overflow. I tested gcc 10.2.1 and 8.2 on different systems (one being the login node of a cluster, the other being my personal computer with a Fedora 32 OS). ASAN seems to report on the copy of the array-section invoked by the omp clause reduction(+ : ptr[:v.size()]) where ptr is a copy of v.data() and v is the std::vector. This does *not* happen when the std::vector is replaced by std::array. The same code does *not* report anything when compiled and ASAN-instrumented with clang 10.0.1. I first filed a issue https://github.com/google/sanitizers/issues/1326 and was sent here. The problem is also *not* reproducible in C when replacing the std::vector with dynamic memory allocated via calloc.