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Niels Lohmann
a55cae45fd
* Test that the contiguous fast paths never read outside the input The bulk string scanner, the SWAR searches, the UTF-8 prefix validator, the 8-digit number loop, the 8-byte indentation skip, and the BSON/BON8 bulk string readers load several bytes at a time from contiguous input. ASan misses over-reads into the slack of the same heap allocation, and fuzzers rarely end an input exactly at a page boundary. The new test copies each input directly in front of, and directly behind, an inaccessible page (mmap/mprotect on POSIX, VirtualAlloc/VirtualProtect on Windows), so reading even one byte outside the input crashes. It covers the string-scan functions directly and json::parse, accept, sax_parse (with and without comments) and all binary readers through the public API, with inputs ending at every byte of strings, escapes, UTF-8 sequences, numbers, literals, indentation runs, and binary documents. Each result must match parsing the same input from a std::string. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Rename the reader parameter to avoid a flawfinder false positive Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Make the guard page test work without exceptions and under UBSan Under JSON_NOEXCEPTION, the error paths abort instead of throwing, so the outcomes are now computed with allow_exceptions=false there. Copying the input with std::copy from char to unsigned char tripped Clang's implicit conversion sanitizer; std::memcpy avoids the conversion. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Test parse_float_native() at the guard page parse_float_eisel_lemire() was removed by #5738, so the test no longer compiled. The lexer converts floats from its token buffer, so the JSON section never places a float token at the page boundary; the section now calls parse_float_native() for float and double on every complete number token directly and compares the result bit for bit with converting the same token from a std::string. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix clang-tidy findings in the guard-page tests Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Convert explicitly between bytes and characters in the guard-page tests The clang sanitizer job (-fsanitize=integer, x86-64 where char is signed) reported the implicit char -> unsigned char conversions of std::copy() into the guarded buffer and of the std::string built from the binary inputs. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>