Hello, We are developing a new fuzzer, and it found a SEGV error in bison 3.8.2.
Stack Trace ==12263==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x7f5b51624306 bp 0x000000000000 sp 0x7ffe4b88e6a8 T0) ==12263==The signal is caused by a READ memory access. ==12263==Hint: address points to the zero page. #0 0x7f5b51624305 (/lib/x86_64-linux-gnu/libc.so.6+0xb1305) #1 0x7f5b515fd5f4 in fputs_unlocked (/lib/x86_64-linux-gnu/libc.so.6+0x8a5f4) #2 0x556acb7e54e7 in yy_symbol_value_print src/parse-gram.y:244 #3 0x556acb7e5d7b in yy_symbol_print src/parse-gram.c:1392 #4 0x556acb7edb4a in gram_parse src/parse-gram.c:2966 #5 0x556acb8077e3 in reader src/reader.c:766 #6 0x556acb7b2be0 in main src/main.c:118 Steps to Reproduce We configured and built bison with address sanitizer: CFLAGS="-fsanitize=address -g -O0" ./configure make -j Then, run bison with: ./bison <attached_file> -T Environment - OS: Ubuntu 18.04.1 - gcc 7.5.0 - bison: 3.8.2 Many Thanks, Youngseok Choi
<<attachment: bison_input_poc1.zip>>