I couldn't get it to generate a coredump. But I ran it with valgrind Hope this helps valgrind -v /usr/sbin/gssproxy --interactive --debug --debug-level=3 --socket=/run/gssproxy.sock ==29249== Memcheck, a memory error detector ==29249== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==29249== Using Valgrind-3.15.0-608cb11914-20190413 and LibVEX; rerun with -h for copyright info ==29249== Command: /usr/sbin/gssproxy --interactive --debug --debug-level=3 --socket=/run/gssproxy.sock ==29249== --29249-- Valgrind options: --29249-- -v --29249-- Contents of /proc/version: --29249-- Linux version 5.4.0-74-generic (buildd@lgw01-amd64-038) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #83-Ubuntu SMP Sat May 8 02:35:39 UTC 2021 --29249-- --29249-- Arch and hwcaps: AMD64, LittleEndian, amd64-cx16-lzcnt-rdtscp-sse3-ssse3-avx-avx2-rdrand --29249-- Page sizes: currently 4096, max supported 4096 --29249-- Valgrind library directory: /usr/lib/x86_64-linux-gnu/valgrind --29249-- Reading syms from /usr/sbin/gssproxy --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/ld-2.31.so --29249-- Considering /usr/lib/x86_64-linux-gnu/ld-2.31.so .. --29249-- .. CRC mismatch (computed 975d0390 wanted 30bd717f) --29249-- Considering /lib/x86_64-linux-gnu/ld-2.31.so .. --29249-- .. CRC mismatch (computed 975d0390 wanted 30bd717f) --29249-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/ld-2.31.so .. --29249-- .. CRC is valid --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/valgrind/memcheck-amd64-linux --29249-- object doesn't have a symbol table --29249-- object doesn't have a dynamic symbol table --29249-- Scheduler: using generic scheduler lock implementation. --29249-- Reading suppressions file: /usr/lib/x86_64-linux-gnu/valgrind/default.supp ==29249== embedded gdbserver: reading from /tmp/vgdb-pipe-from-vgdb-to-29249-by-root-on-??? ==29249== embedded gdbserver: writing to /tmp/vgdb-pipe-to-vgdb-from-29249-by-root-on-??? ==29249== embedded gdbserver: shared mem /tmp/vgdb-pipe-shared-mem-vgdb-29249-by-root-on-??? ==29249== ==29249== TO CONTROL THIS PROCESS USING vgdb (which you probably ==29249== don't want to do, unless you know exactly what you're doing, ==29249== or are doing some strange experiment): ==29249== /usr/lib/x86_64-linux-gnu/valgrind/../../bin/vgdb --pid=29249 ...command... ==29249== ==29249== TO DEBUG THIS PROCESS USING GDB: start GDB like this ==29249== /path/to/gdb /usr/sbin/gssproxy ==29249== and then give GDB the following command ==29249== target remote | /usr/lib/x86_64-linux-gnu/valgrind/../../bin/vgdb --pid=29249 ==29249== --pid is optional if only one valgrind process is running ==29249== --29249-- REDIR: 0x4022e10 (ld-linux-x86-64.so.2:strlen) redirected to 0x580c9ce2 (???) --29249-- REDIR: 0x4022be0 (ld-linux-x86-64.so.2:index) redirected to 0x580c9cfc (???) --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_core-amd64-linux.so --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so --29249-- object doesn't have a symbol table ==29249== WARNING: new redirection conflicts with existing -- ignoring it --29249-- old: 0x04022e10 (strlen ) R-> (0000.0) 0x580c9ce2 ??? --29249-- new: 0x04022e10 (strlen ) R-> (2007.0) 0x0483f060 strlen --29249-- REDIR: 0x401f5f0 (ld-linux-x86-64.so.2:strcmp) redirected to 0x483ffd0 (strcmp) --29249-- REDIR: 0x4023370 (ld-linux-x86-64.so.2:mempcpy) redirected to 0x4843a20 (mempcpy) --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libpopt.so.0.0.0 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libkrb5.so.3.3 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libk5crypto.so.3.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libverto.so.1.0.0 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libini_config.so.5.2.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libref_array.so.1.2.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libselinux.so.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libgssrpc.so.4.2 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2.2 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libpthread-2.31.so --29249-- Considering /usr/lib/debug/.build-id/e5/4761f7b554d0fcc1562959665d93dffbebdaf0.debug .. --29249-- .. build-id is valid --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libc-2.31.so --29249-- Considering /usr/lib/x86_64-linux-gnu/libc-2.31.so .. --29249-- .. CRC mismatch (computed 86b78530 wanted e380f01c) --29249-- Considering /lib/x86_64-linux-gnu/libc-2.31.so .. --29249-- .. CRC mismatch (computed 86b78530 wanted e380f01c) --29249-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.31.so .. --29249-- .. CRC is valid --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libcom_err.so.2.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libkrb5support.so.0.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libkeyutils.so.1.8 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libresolv-2.31.so --29249-- Considering /usr/lib/x86_64-linux-gnu/libresolv-2.31.so .. --29249-- .. CRC mismatch (computed 240175c5 wanted 37ae7771) --29249-- Considering /lib/x86_64-linux-gnu/libresolv-2.31.so .. --29249-- .. CRC mismatch (computed 240175c5 wanted 37ae7771) --29249-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libresolv-2.31.so .. --29249-- .. CRC is valid --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libdl-2.31.so --29249-- Considering /usr/lib/x86_64-linux-gnu/libdl-2.31.so .. --29249-- .. CRC mismatch (computed b5d487d3 wanted 6ef97e7c) --29249-- Considering /lib/x86_64-linux-gnu/libdl-2.31.so .. --29249-- .. CRC mismatch (computed b5d487d3 wanted 6ef97e7c) --29249-- Considering /usr/lib/debug/lib/x86_64-linux-gnu/libdl-2.31.so .. --29249-- .. CRC is valid --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libcollection.so.4.1.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libpath_utils.so.1.0.1 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libbasicobjects.so.0.1.0 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libpcre2-8.so.0.9.0 --29249-- object doesn't have a symbol table --29249-- REDIR: 0x4af8600 (libc.so.6:memmove) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af7900 (libc.so.6:strncpy) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8930 (libc.so.6:strcasecmp) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af7220 (libc.so.6:strcat) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af7960 (libc.so.6:rindex) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af9dd0 (libc.so.6:rawmemchr) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b14e60 (libc.so.6:wmemchr) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b149a0 (libc.so.6:wcscmp) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8760 (libc.so.6:mempcpy) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8590 (libc.so.6:bcmp) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af7890 (libc.so.6:strncmp) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af72d0 (libc.so.6:strcmp) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af86c0 (libc.so.6:memset) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b14960 (libc.so.6:wcschr) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af77f0 (libc.so.6:strnlen) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af73b0 (libc.so.6:strcspn) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8980 (libc.so.6:strncasecmp) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af7350 (libc.so.6:strcpy) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8ad0 (libc.so.6:memcpy@@GLIBC_2.14) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b160d0 (libc.so.6:wcsnlen) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b149e0 (libc.so.6:wcscpy) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af79a0 (libc.so.6:strpbrk) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af7280 (libc.so.6:index) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af77b0 (libc.so.6:strlen) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b00d20 (libc.so.6:memrchr) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af89d0 (libc.so.6:strcasecmp_l) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8550 (libc.so.6:memchr) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b14ab0 (libc.so.6:wcslen) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af7c60 (libc.so.6:strspn) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af88d0 (libc.so.6:stpncpy) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8870 (libc.so.6:stpcpy) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af9e10 (libc.so.6:strchrnul) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8a20 (libc.so.6:strncasecmp_l) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4b858e0 (libc.so.6:__memcpy_chk) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4af8470 (libc.so.6:strstr) redirected to 0x48311d0 (_vgnU_ifunc_wrapper) --29249-- REDIR: 0x4be0490 (libc.so.6:__strrchr_avx2) redirected to 0x483ea10 (rindex) --29249-- REDIR: 0x4af2260 (libc.so.6:malloc) redirected to 0x483b780 (malloc) --29249-- REDIR: 0x4af8120 (libc.so.6:__GI_strstr) redirected to 0x4843ca0 (__strstr_sse2) --29249-- REDIR: 0x4bdc4c0 (libc.so.6:__memchr_avx2) redirected to 0x4840050 (memchr) --29249-- REDIR: 0x4be3670 (libc.so.6:__memcpy_avx_unaligned_erms) redirected to 0x48429f0 (memmove) --29249-- REDIR: 0x4b13560 (libc.so.6:__strstr_sse2_unaligned) redirected to 0x4843c20 (strstr) --29249-- REDIR: 0x4af2850 (libc.so.6:free) redirected to 0x483c9d0 (free) --29249-- REDIR: 0x4be0660 (libc.so.6:__strlen_avx2) redirected to 0x483ef40 (strlen) --29249-- REDIR: 0x4be2890 (libc.so.6:__stpcpy_avx2) redirected to 0x4842300 (stpcpy) --29249-- REDIR: 0x4be3650 (libc.so.6:__mempcpy_avx_unaligned_erms) redirected to 0x4843660 (mempcpy) --29249-- REDIR: 0x4af3c90 (libc.so.6:calloc) redirected to 0x483dce0 (calloc) --29249-- REDIR: 0x4bdbfa0 (libc.so.6:__strncmp_avx2) redirected to 0x483f670 (strncmp) --29249-- REDIR: 0x4be1ba0 (libc.so.6:__strcpy_avx2) redirected to 0x483f090 (strcpy) --29249-- REDIR: 0x4a9e670 (libc.so.6:setenv) redirected to 0x4844480 (setenv) --29249-- REDIR: 0x4be0070 (libc.so.6:__strchr_avx2) redirected to 0x483ebf0 (index) --29249-- REDIR: 0x4af3000 (libc.so.6:realloc) redirected to 0x483df30 (realloc) --29249-- REDIR: 0x4bdcc50 (libc.so.6:__memcmp_avx2_movbe) redirected to 0x48421e0 (bcmp) --29249-- REDIR: 0x4be3af0 (libc.so.6:__memset_avx2_unaligned_erms) redirected to 0x48428e0 (memset) --29249-- REDIR: 0x4be02a0 (libc.so.6:__strchrnul_avx2) redirected to 0x4843540 (strchrnul) [2021/06/29 13:55:21]: Debug Enabled (level: 3) --29249-- REDIR: 0x4bdbb60 (libc.so.6:__strcmp_avx2) redirected to 0x483fed0 (strcmp) --29249-- REDIR: 0x4be0800 (libc.so.6:__strnlen_avx2) redirected to 0x483eee0 (strnlen) --29249-- REDIR: 0x4bde6b0 (libc.so.6:__strncasecmp_avx) redirected to 0x483f910 (strncasecmp) --29249-- REDIR: 0x4bdd030 (libc.so.6:__strcasecmp_avx) redirected to 0x483f830 (strcasecmp) --29249-- REDIR: 0x4bdba30 (libc.so.6:__strspn_sse42) redirected to 0x4843ef0 (strspn) --29249-- REDIR: 0x4bdb7b0 (libc.so.6:__strcspn_sse42) redirected to 0x4843e10 (strcspn) --29249-- REDIR: 0x4be1f30 (libc.so.6:__strncpy_avx2) redirected to 0x483f230 (strncpy) [2021/06/29 13:55:21]: Service: nfs-client, Keytab: /etc/krb5.keytab, Enctype: 23 [2021/06/29 13:55:21]: Service: nfs-server, Keytab: /etc/krb5.keytab, Enctype: 23 --29249-- REDIR: 0x4bdd044 (libc.so.6:__strcasecmp_l_avx) redirected to 0x483fab0 (strcasecmp_l) --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libverto-libevent.so.1.0.0 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0 --29249-- object doesn't have a symbol table --29249-- Discarding syms at 0x55ca300-0x55ca766 in /usr/lib/x86_64-linux-gnu/libverto-libevent.so.1.0.0 (have_dinfo 1) --29249-- Discarding syms at 0x55e4c20-0x5617271 in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0 (have_dinfo 1) --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libverto-libevent.so.1.0.0 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0 --29249-- object doesn't have a symbol table --29249-- Discarding syms at 0x55ca300-0x55ca766 in /usr/lib/x86_64-linux-gnu/libverto-libevent.so.1.0.0 (have_dinfo 1) --29249-- Discarding syms at 0x55e4c20-0x5617271 in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0 (have_dinfo 1) --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libverto-libevent.so.1.0.0 --29249-- object doesn't have a symbol table --29249-- Reading syms from /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0 --29249-- object doesn't have a symbol table [2021/06/29 13:55:21]: Client [2021/06/29 13:55:21]: (/usr/sbin/gssproxy) [2021/06/29 13:55:21]: connected (fd = 13)[2021/06/29 13:55:21]: (pid = 29249) (uid = 0) (gid = 0)==29249== Invalid read of size 8 ==29249== at 0x49A695E: context_str (in /usr/lib/x86_64-linux-gnu/libselinux.so.1) ==29249== by 0x1126AC: ??? (in /usr/sbin/gssproxy) ==29249== by 0x497434B: verto_fire (in /usr/lib/x86_64-linux-gnu/libverto.so.1.0.0) ==29249== by 0x55F913E: ??? (in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0) ==29249== by 0x55F987E: event_base_loop (in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0) ==29249== by 0x10F173: ??? (in /usr/sbin/gssproxy) ==29249== by 0x4A7C0B2: (below main) (libc-start.c:308) ==29249== Address 0x0 is not stack'd, malloc'd or (recently) free'd ==29249== ==29249== ==29249== Process terminating with default action of signal 11 (SIGSEGV) ==29249== Access not within mapped region at address 0x0 ==29249== at 0x49A695E: context_str (in /usr/lib/x86_64-linux-gnu/libselinux.so.1) ==29249== by 0x1126AC: ??? (in /usr/sbin/gssproxy) ==29249== by 0x497434B: verto_fire (in /usr/lib/x86_64-linux-gnu/libverto.so.1.0.0) ==29249== by 0x55F913E: ??? (in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0) ==29249== by 0x55F987E: event_base_loop (in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0) ==29249== by 0x10F173: ??? (in /usr/sbin/gssproxy) ==29249== by 0x4A7C0B2: (below main) (libc-start.c:308) ==29249== If you believe this happened as a result of a stack ==29249== overflow in your program's main thread (unlikely but ==29249== possible), you can try to increase the size of the ==29249== main thread stack using the --main-stacksize= flag. ==29249== The main thread stack size used in this run was 8388608. ==29249== ==29249== HEAP SUMMARY: ==29249== in use at exit: 18,699 bytes in 154 blocks ==29249== total heap usage: 2,717 allocs, 2,563 frees, 485,171 bytes allocated ==29249== ==29249== Searching for pointers to 154 not-freed blocks ==29249== Checked 42,193,384 bytes ==29249== ==29249== LEAK SUMMARY: ==29249== definitely lost: 0 bytes in 0 blocks ==29249== indirectly lost: 0 bytes in 0 blocks ==29249== possibly lost: 1,600 bytes in 5 blocks ==29249== still reachable: 17,099 bytes in 149 blocks ==29249== suppressed: 0 bytes in 0 blocks ==29249== Rerun with --leak-check=full to see details of leaked memory ==29249== ==29249== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) ==29249== ==29249== 1 errors in context 1 of 1: ==29249== Invalid read of size 8 ==29249== at 0x49A695E: context_str (in /usr/lib/x86_64-linux-gnu/libselinux.so.1) ==29249== by 0x1126AC: ??? (in /usr/sbin/gssproxy) ==29249== by 0x497434B: verto_fire (in /usr/lib/x86_64-linux-gnu/libverto.so.1.0.0) ==29249== by 0x55F913E: ??? (in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0) ==29249== by 0x55F987E: event_base_loop (in /usr/lib/x86_64-linux-gnu/libevent-2.1.so.7.0.0) ==29249== by 0x10F173: ??? (in /usr/sbin/gssproxy) ==29249== by 0x4A7C0B2: (below main) (libc-start.c:308) ==29249== Address 0x0 is not stack'd, malloc'd or (recently) free'd ==29249== ==29249== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) Segmentation fault