[Bug libstdc++/88923] New: abi::__cxa_demangle segfault on a specific string

[antanubis at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88923

            Bug ID: 88923
           Summary: abi::__cxa_demangle segfault on a specific string
           Product: gcc
           Version: 7.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: antanubis at gmail dot com
  Target Milestone: ---

I use "dump_syms" util from Google Breakpad to extract debug symbols from my
binaries and at some version it started segfaulting. I've found the exact
string on which the call to abi::__cxa_demangle crashes and it reproduces in a
standalone example (name 'test.cpp'):

#include <cxxabi.h>
#include <iostream>
int main() {
        const char *symbol =
"_ZNSt11_Tuple_implILm0EJN3rpl8producerIN4base5flagsIN11MTPDchannel4FlagEEENS0_8no_errorEZNS0_7details10map_helperIZN4Data18FlagsValueWithMaskINSA_5FlagsIS6_Lj2147486693EE6ChangeES7_ZNS8_11then_helperISE_S7_ZNKS0_12event_streamISE_E6eventsEvEUlRKT_E_EclISE_S7_ZNS0_6singleISE_EEDaOSI_EUlSK_E_SE_S7_EEDaONS1_ISI_T0_T1_EEEUlSK_E_EEDaSU_NSI_4TypeEEUlRKSE_E0_EclISE_S7_ZNS8_13filter_helperIZNSB_ISE_S7_SV_EEDaSU_SW_EUlSY_E_EclISE_S7_SV_vEEDaSU_EUlSK_E_S6_EEDaSU_EUlSK_E_EENS1_IbS7_ZNS9_IZNSA_15SingleFlagValueINSC_INS3_IN19MTPDchatAdminRights4FlagEEELj4294967295EE6ChangeES7_ZNSF_IS1E_S7_ZNKSG_IS1E_E6eventsEvEUlSK_E_EclIS1E_S7_ZNSO_IS1E_EEDaSP_EUlSK_E_S1E_S7_EEDaSU_EUlSK_E_EEDaSU_NSI_4EnumEEUlS1C_E_EclIS1C_S7_ZNS9_IZNSB_IS1E_S7_S1K_EEDaSU_SW_EUlRKS1E_E0_EclIS1E_S7_ZNS12_IZNSB_IS1E_S7_S1K_EEDaSU_SW_EUlS1Q_E_EclIS1E_S7_S1K_vEEDaSU_EUlSK_E_S1C_EEDaSU_EUlSK_E_bEEDaSU_EUlSK_E_EENS1_IbS7_ZNS9_IZNS19_INSC_INS3_IN20MTPDchatBannedRights4FlagEEELj4294967295EE6ChangeES7_ZNSF_IS25_S7_ZNKSG_IS25_E6eventsEvEUlSK_E_EclIS25_S7_ZNSO_IS25_EEDaSP_EUlSK_E_S25_S7_EEDaSU_EUlSK_E_EEDaSU_S1L_EUlS23_E_EclIS23_S7_ZNS9_IZNSB_IS25_S7_S2B_EEDaSU_SW_EUlRKS25_E0_EclIS25_S7_ZNS12_IZNSB_IS25_S7_S2B_EEDaSU_SW_EUlS2G_E_EclIS25_S7_S2B_vEEDaSU_EUlSK_E_S23_EEDaSU_EUlSK_E_bEEDaSU_EUlSK_E_EES2Q_EED2Ev.lto_priv.19273";
        int status = 0;
        char* demangled_c =
                abi::__cxa_demangle(symbol, NULL, NULL, &status);
        if (status == 0) {
                std::cout << demangled_c << std::endl;
        } else {
                std::cout << "Error: " << status << std::endl;
        }
        if (demangled_c) {
                free(reinterpret_cast<void*>(demangled_c));
        }
        return 0;
}

This program compiled with "gcc test.cpp -lstdc++" crashes for me on gcc 7.4 on
Ubuntu 14.04 and on gcc 7.3 on Ubuntu 18.04.