https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89215
Bug ID: 89215
Summary: UBSAN leaks memory
Product: gcc
Version: 8.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: mail at milianw 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: ---
```
Direct leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x7f668faa7491 in __interceptor_realloc
/build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cc:105
#1 0x7f666e7e5ad3 in d_growable_string_resize
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:3983
#2 0x7f666e7e5ad3 in d_growable_string_append_buffer
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:4007
#3 0x7f666e7e5ad3 in d_growable_string_callback_adapter
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:4024
#4 0x7f666e7ee822 in d_print_flush
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:4222
#5 0x7f666e7ee822 in d_print_callback
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:4308
#6 0x7f666e7ee822 in d_demangle_callback
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:6277
#7 0x7f666e7eead0 in d_demangle
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:6299
#8 0x7f666e7eead0 in __cxa_demangle
/build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/cp-demangle.c:6363
#9 0x7f666dacd4f0 in __sanitizer::DemangleCXXABI(char const*)
/build/gcc/src/gcc/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc:59
#10 0x7f666dacd4f0 in __sanitizer::DemangleCXXABI(char const*)
/build/gcc/src/gcc/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc:51
#11 0x7f666dacd4f0 in __sanitizer::DemangleSwiftAndCXX(char const*)
/build/gcc/src/gcc/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc:100
#12 0x7f666dacd4f0 in __sanitizer::DemangleSwiftAndCXX(char const*)
/build/gcc/src/gcc/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc:96
#13 0x7f666dacc64b in __sanitizer::Symbolizer::Demangle(char const*)
/build/gcc/src/gcc/libsanitizer/sanitizer_common/sanitizer_symbolizer_libcdep.cc:143
#14 0x7f666dab035a in RenderText
/build/gcc/src/gcc/libsanitizer/ubsan/ubsan_diag.cc:189
#15 0x7f666dab0e68 in __ubsan::Diag::~Diag()
/build/gcc/src/gcc/libsanitizer/ubsan/ubsan_diag.cc:357
#16 0x7f666dab5bb1 in HandleDynamicTypeCacheMiss
/build/gcc/src/gcc/libsanitizer/ubsan/ubsan_handlers_cxx.cc:67
#17 0x7f666dab5f14 in __ubsan_handle_dynamic_type_cache_miss
/build/gcc/src/gcc/libsanitizer/ubsan/ubsan_handlers_cxx.cc:85
<stack continues>
```
Note that the `<stack continues>` points at my code, for which I got an UBSAN
warning before. So it seems like UBSAN itself leaked the memory!
Using sanitizers from gcc (GCC) 8.2.1 20181127 from Arch. I can reproduce this
with a commercial project I'm working on, so if there's something I should try
out I'm all ears.
