Comment 4 for bug 1715641

I think there is at least a bug in network-manager: it defines (for whatever reason) an explicit_bzero function, which is not used when building with -D_FORTIFY_SOURCE. The reference in string_erase is transformed from explicit_bzero to explicit_bzero_chk. So if network-manager defines explicit_bzero, then it should define explicit_bzero_chk as well.

Note that linking with gold (both 2.28 and 2.29) you end up with an undefined symbol GLIBC_2.25 __explicit_bzero_chk.

The bfd linker however seems to optimize that out, and doesn't leave any undefined symbol. However in ld-2.29 it leaves a reference in

Version needs section '.gnu.version_r' contains 9 entries:

  0x0170: Name: GLIBC_2.25 Flags: none Version: 11

Removing this unused explicit_bzero function seems to work, and the string-util.h is not installed anywhere, it shouldn't be part of any API.