SEGV in src/memory/SharedPtr.hpp:116

[strongcourage]

Hi,

I found a null pointer dereferencing bug in the latest commit eb54de6 on master.
PoC: https://github.com/strongcourage/PoCs/blob/master/libsaas_eb54de6/PoC_npd_SharedPtr.hpp:116
Command: sassc $PoC
ASAN says:

==30919==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x0000005a4c96 bp 0x7ffe2b9cc400 sp 0x7ffe2b9cbcf0 T0)
    #0 0x5a4c95 in Sass::SharedPtr::SharedPtr(Sass::SharedPtr const&) src/memory/SharedPtr.hpp:116
    #1 0x5a4c95 in Sass::SharedImpl<Sass::SimpleSelector>::SharedImpl(Sass::SharedImpl<Sass::SimpleSelector> const&) src/memory/SharedPtr.hpp:183
    #2 0x5a4c95 in Sass::Parser::parseCompoundSelector() src/parser_selectors.cpp:143
    #3 0x5a9da8 in Sass::Parser::parseComplexSelector(bool) src/parser_selectors.cpp:42
    #4 0x5ab21b in Sass::Parser::parseSelectorList(bool) src/parser_selectors.cpp:82
    #5 0x58982a in Sass::Parser::parse_ruleset(Lookahead) src/parser.cpp:530
    #6 0x5833e7 in Sass::Parser::parse_block_node(bool) src/parser.cpp:278
    #7 0x583cc7 in Sass::Parser::parse_block_nodes(bool) src/parser.cpp:189
    #8 0x585410 in Sass::Parser::parse() src/parser.cpp:115
    #9 0x440317 in Sass::Context::register_resource(Sass::Include const&, Sass::Resource const&) src/context.cpp:306
    #10 0x4412d1 in Sass::File_Context::parse() src/context.cpp:576
    #11 0x428509 in sass_parse_block src/sass_context.cpp:180
    #12 0x428509 in sass_compiler_parse src/sass_context.cpp:434
    #13 0x429038 in sass_compile_context src/sass_context.cpp:317
    #14 0x420b95 in compile_file /home/dungnguyen/gueb-testing/libsass/sassc/sassc.c:173
    #15 0x40992f in main /home/dungnguyen/gueb-testing/libsass/sassc/sassc.c:387
    #16 0x7f9f2161382f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #17 0x420598 in _start (/home/dungnguyen/PoCs/libsaas_eb54de6/sassc-asan+0x420598)

Thanks,
Manh Dung

[mgreter]

Duplicate of #3001