segfault in ini_lex() in 7.0.3

I got a core dump with this output:

Can you provide the INI (minus secure info) and script that generates
this?

Cannot access memory at address 0x9
Cannot access memory at address 0x1

#0 0x0000000000654a6d in ini_lex (ini_lval=0xd314c15417d73c46)
at Zend/zend_ini_scanner.c:3724
#1 0x000000000067da19 in init_executor ()
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_execute_API.c:176
#2 0x0000000000669862 in zend_string_alloc (persistent=0,
len=140720308486145)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_string.h:134
#3 zend_string_init (persistent=0, len=18446744069414584336, str=0x0)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_string.h:157
#4 zend_compile_dynamic_call (result=0x7f2afa13e8a0,
name_node=0x7f0200000040, args_ast=0x67da19 <init_executor+499>)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:2867
#5 0x0000000000671e99 in zend_compile_class_decl (ast=0x7f2afa389910)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:5262
#6 0x00000000006678ad in zend_compile_dim (result=0x7f2afa154268,
ast=0x7f2afa154268, type=32554)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:2301
#7 0x0000000000671d62 in zend_compile_class_decl (ast=0x7f2afa1f77c0)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:5242
#8 0x000000000066b307 in zend_ast_get_list (ast=0x7f2af9eaf7e0)
at /wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_ast.h:221
#9 zend_compile_call (result=0x7f2af9e527e0, ast=0x7ffc412f7f50,
type=32554)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:3236
#10 0x0000000000671eda in zend_compile_class_decl (ast=0x7f2af9ea2a50)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:5262
#11 0x0000000000671b11 in zend_compile_class_decl (ast=0x12de10)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:5208
#12 0x0000000000671af3 in zend_string_release (s=0x0)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_string.h:271
#13 zend_compile_class_decl (ast=0x7f2b4e7ced50)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:5207
#14 0x0000000000629310 in zendparse ()
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_language_parser.c:4357
#15 0x000000000067666e in zend_string_alloc (persistent=32554, len=32768)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_string.h:121
#16 zend_string_init (persistent=32764, len=0,
str=0x10005d1a00 <Address 0x10005d1a00 out of bounds>)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_string.h:157
#17 zend_compile_shell_exec (result=0x0, ast=0x0)
at
/wayfair/home/cmccoy/rpmbuild/BUILD/php-7.0.3/Zend/zend_compile.c:6438
#18 0x00007f2b47e8e202 in ?? ()
#19 0x00007ffc412f92f8 in ?? ()
#20 0x0000000000000000 in ?? ()

I found this bug which sounds a little similar, though it appears to have
been fixed:
https://bugs.php.net/bug.php?id=70748

Does anyone have any suggestions for how to debug?

Thanks,
Adam