Hello, We are currently working on fuzz testing feature, and we found a *SEGV* error on `bison`.
The stack traces are as follow: ==29725==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 > (pc 0x5577cbd45d4a bp 0x7ffda59e9300 sp 0x7ffda59e7260 T0) > ==29725==The signal is caused by a READ memory access. > ==29725==Hint: address points to the zero page. > #0 0x5577cbd45d49 in intersect src/lssi.c:297 > #1 0x5577cbd46333 in lssi_reverse_production src/lssi.c:361 > #2 0x5577cbd8ab93 in simulate_reduction src/parse-simulation.c:536 > #3 0x5577cbd166f2 in reduction_step src/counterexample.c:834 > #4 0x5577cbd1849e in generate_next_states src/counterexample.c:1047 > #5 0x5577cbd19417 in unifying_example src/counterexample.c:1182 > #6 0x5577cbd19e04 in counterexample_report src/counterexample.c:1277 > #7 0x5577cbd1ae65 in counterexample_report_reduce_reduce > src/counterexample.c:1350 > #8 0x5577cbd1b863 in counterexample_report_state > src/counterexample.c:1394 > #9 0x5577cbd952e0 in print_state src/print.c:366 > #10 0x5577cbd9617a in print_results src/print.c:473 > #11 0x5577cbd46ee4 in main src/main.c:188 The full stack trace is attached. - *Step to reproduce* We configured `bison` using `*CFLAGS="-g -O0 -fsanitize=address" ./configure --prefix=$(pwd)/ --disable-shared*` and build it using `*make -j 10*`, and run it with: ./bison --feature=caret --debug --report=all --graph=all -p > --graph=precedence <attached file> --verbose The input file is attached. - *Environment* - OS: Ubuntu 18.04.5 LTS - GCC version: gcc 7.5.0 - Bison version: latest commit (7c90a28) of master branch in github ([link]( https://github.com/akimd/bison/tree/7c90a28f17e97b3ec8213ff6e0b0a5d2382f8929 )) Thank you.
<<attachment: full_stacktrace_poc_2.zip>>
<<attachment: input_bison_poc_2.zip>>
