valgrind: add valgrind suppression for memmove() overlapth/tmp6

This valgrind error is raised by Ubuntu 23:10, with valgrind 1:3.21.0-0ubuntu1 and
glibc 2.38-1ubuntu6:

  ==141967== Source and destination overlap in memcpy_chk(0x1ffefffe98, 0x1ffefffe92, 8)
  ==141967==    at 0x4851042: __memcpy_chk (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==141967==    by 0x502A9CC: memmove (string_fortified.h:36)
  ==141967==    by 0x502A9CC: inet_pton6 (inet_pton.c:226)
  ==141967==    by 0x502A9CC: __inet_pton_length (inet_pton.c:56)
  ==141967==    by 0x502A9CC: inet_pton (inet_pton.c:69)
  ==141967==    by 0x114FA3: nmtst_inet6_from_string_p (nm-test-utils.h:1764)
  ==141967==    by 0x114FA3: _nmtst_assert_ip6_address (nm-test-utils.h:1856)
  ==141967==    by 0x114FA3: test_stable_privacy (test-utils.c:26)
  ==141967==    by 0x4DEC85D: ??? (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.7800.0)
  ==141967==    by 0x4DEC78A: ??? (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.7800.0)
  ==141967==    by 0x4DECD2A: g_test_run_suite (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.7800.0)
  ==141967==    by 0x4DECE07: g_test_run (in /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.7800.0)
  ==141967==    by 0x4F070CF: (below main) (libc_start_call_main.h:58)
  ==141967==
  {
     <insert_a_suppression_name_here>
     Memcheck:Overlap
     fun:__memcpy_chk
     fun:memmove
     fun:inet_pton6
     fun:__inet_pton_length
     fun:inet_pton
     fun:nmtst_inet6_from_string_p
     fun:_nmtst_assert_ip6_address
     fun:test_stable_privacy
     obj:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.7800.0
     obj:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0.7800.0
     fun:g_test_run_suite
     fun:g_test_run
     fun:(below main)
  }

Its not clear to me, why this would happen. In any case, it seems like a false
positive. Add a suppression.

1 files changed, 10 insertions, 0 deletions

diff --git a/valgrind.suppressions b/valgrind.suppressions
index 3109671ae6..0552625192 100644
--- a/valgrind.suppressions
+++ b/valgrind.suppressions
@@ -499,3 +499,13 @@
    fun:btrfs_reflink_with_progress
    ...
 }
+{
+   _memmove_overlap
+   Memcheck:Overlap
+   fun:__memcpy_chk
+   fun:memmove
+   fun:inet_pton6
+   fun:__inet_pton_length
+   fun:inet_pton
+   ...
+}