[perl #129105] null ptr deref, segfault Perl_newSVpv (sv.c:9218)

# New Ticket Created by  Brian Carpenter 
# Please include the string:  [perl #129105]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=129105 >


Fuzzing Perl v5.25.4-20-gc2f7c0b* with AFL, ASAN and libdislocator.

./perl -e 'unpack+p,w0000000'

==23795==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x7f648b2aec3a bp 0x7ffd3b494e80 sp 0x7ffd3b494618 T0)
    #0 0x7f648b2aec39 in strlen /build/glibc-uPj9cH/glibc-2.19/string/../sysdeps/x86_64/strlen.S:76
    #1 0x4abacb in __interceptor_strlen (/root/perl/perl+0x4abacb)
    #2 0x962587 in Perl_newSVpv /root/perl/sv.c:9218:5
    #3 0xc547ed in S_unpack_rec /root/perl/pp_pack.c:1564:3
    #4 0xc4b955 in Perl_unpackstring /root/perl/pp_pack.c:835:12
    #5 0xc61499 in Perl_pp_unpack /root/perl/pp_pack.c:1839:11
    #6 0x7f1c63 in Perl_runops_debug /root/perl/dump.c:2234:23
    #7 0x5a10a6 in S_run_body /root/perl/perl.c:2525:2
    #8 0x5a10a6 in perl_run /root/perl/perl.c:2448
    #9 0x4de6cd in main /root/perl/perlmain.c:123:9
    #10 0x7f648b24eb44 in __libc_start_main /build/glibc-uPj9cH/glibc-2.19/csu/libc-start.c:287
    #11 0x4de33c in _start (/root/perl/perl+0x4de33c)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /build/glibc-uPj9cH/glibc-2.19/string/../sysdeps/x86_64/strlen.S:76 strlen
==23795==ABORTING

• [perl #129105] null ptr deref, segfault Perl_newSVpv (sv.c:9218) by Dan Collins via RT
• [perl #129105] null ptr deref, segfault Perl_newSVpv (sv.c:9218) by Father Chrysostomos via RT
• [perl #129105] null ptr deref, segfault Perl_newSVpv (sv.c:9218) by Father Chrysostomos via RT
• [perl #129105] null ptr deref, segfault Perl_newSVpv (sv.c:9218) by Brian Carpenter