AddressSanitizer: stack-buffer-overflow in jq_fuzz_execute (jv_string_vfmt)

jq is a command-line JSON processor. In versions up to and including 1.7.1, a heap-buffer-overflow is present in function `jv_string_vfmt` in the jq_fuzz_execute harness from oss-fuzz. This crash happens on file jv.c, line 1456 `void* p = malloc(sz);`. As of time of publication, no patched versions are available.