mknames crashes by default during the compile time

[asarubbo]

To reproduce it is enough to compile with -fsanitize=address:

echo '#include <elf.h>' | gcc -E -dM -xc /dev/stdin | ./mknames elfnames.c
=================================================================
==206==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000000d7 at pc 0x0000004325e9 bp 0x7fff066f4380 sp 0x7fff066f3b28
READ of size 9 at 0x6020000000d7 thread T0
    #0 0x4325e8 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) /var/tmp/portage/sys-libs/compiler-rt-sanitizers-9.0.0/work/compiler-rt-9.0.0.src/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:834:7
    #1 0x432b3a in bcmp /var/tmp/portage/sys-libs/compiler-rt-sanitizers-9.0.0/work/compiler-rt-9.0.0.src/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:880:10
    #2 0x4c2e8e in readdefine /var/tmp/portage/dev-util/elfkickers-3.1/work/ELFkickers-3.1/elftoc/mknames.c:197:7
    #3 0x4c2e8e in readinput /var/tmp/portage/dev-util/elfkickers-3.1/work/ELFkickers-3.1/elftoc/mknames.c:227:2
    #4 0x4c2e8e in main /var/tmp/portage/dev-util/elfkickers-3.1/work/ELFkickers-3.1/elftoc/mknames.c:363:5
    #5 0x7ff3011d1dca in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.29-r2/work/glibc-2.29/csu/../csu/libc-start.c:308:16
    #6 0x41b369 in _start (/var/tmp/portage/dev-util/elfkickers-3.1/work/ELFkickers-3.1/elftoc/mknames+0x41b369)

0x6020000000d7 is located 0 bytes to the right of 7-byte region [0x6020000000d0,0x6020000000d7)
allocated by thread T0 here:
    #0 0x49325d in malloc /var/tmp/portage/sys-libs/compiler-rt-sanitizers-9.0.0/work/compiler-rt-9.0.0.src/lib/asan/asan_malloc_linux.cc:145:3
    #1 0x4c2dc1 in readdefine /var/tmp/portage/dev-util/elfkickers-3.1/work/ELFkickers-3.1/elftoc/mknames.c:193:12
    #2 0x4c2dc1 in readinput /var/tmp/portage/dev-util/elfkickers-3.1/work/ELFkickers-3.1/elftoc/mknames.c:227:2
    #3 0x4c2dc1 in main /var/tmp/portage/dev-util/elfkickers-3.1/work/ELFkickers-3.1/elftoc/mknames.c:363:5
    #4 0x7ff3011d1dca in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.29-r2/work/glibc-2.29/csu/../csu/libc-start.c:308:16

SUMMARY: AddressSanitizer: heap-buffer-overflow /var/tmp/portage/sys-libs/compiler-rt-sanitizers-9.0.0/work/compiler-rt-9.0.0.src/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:834:7 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long)
Shadow bytes around the buggy address:
  0x0c047fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff8000: fa fa 00 07 fa fa fd fd fa fa 00 07 fa fa fd fd
=>0x0c047fff8010: fa fa 00 06 fa fa 00 05 fa fa[07]fa fa fa fa fa
  0x0c047fff8020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8060: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==206==ABORTING

[BR903]

Good catch, should be fixed now.

[asarubbo]

I spotted it during the compilation via the Gentoo Package manager. If you can issue a minor release you will facilitate us. Thanks in advance.

[BR903]

I spotted it during the compilation via the Gentoo Package manager. If you can issue a minor release you will facilitate us. Thanks in advance.

It's been almost exactly three years since the last release; it's a good time to make another one. b