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834b8123ef
Don't create a copy of the whole input buffer. Read the data chunk by chunk to save memory. Historically, it was probably envisioned to read data from memory without additional copying. This doesn't work reliably with the current design of the XML parser which requires a terminating null byte at the end of input buffers. This lead to xmlReadMemory interfaces, which expect pointer and size arguments, being changed to make a zero-terminated copy of the input buffer. Interfaces based on xmlReadDoc, which actually expect a zero-terminated string and would make zero-copy operation work, were then simplified to rely on xmlReadMemoryi, resulting in an unnecessary copy. To avoid copying (possibly gigabytes) of memory temporarily, we now stream in-memory input just like content read from files in a chunk-by-chunk fashion (using a somewhat outdated INPUT_CHUNK size of 250 bytes). As a side effect, we also avoid another copy of the whole input when handling non-UTF-8 data which was made possible by some earlier commits. Interfaces expecting zero-terminated strings now make use of strnlen which unfortunately isn't part of the standard C library and only mandated since POSIX 2008. |
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| .. | ||
| static_seed | ||
| .gitignore | ||
| fuzz.c | ||
| fuzz.h | ||
| genSeed.c | ||
| html.c | ||
| html.dict | ||
| html.options | ||
| Makefile.am | ||
| README | ||
| regexp.c | ||
| regexp.dict | ||
| regexp.options | ||
| schema.c | ||
| schema.dict | ||
| schema.options | ||
| testFuzzer.c | ||
| uri.c | ||
| uri.options | ||
| valid.c | ||
| valid.options | ||
| xinclude.c | ||
| xinclude.options | ||
| xml.c | ||
| xml.dict | ||
| xml.options | ||
| xpath.c | ||
| xpath.dict | ||
| xpath.options | ||
libFuzzer instructions for libxml2
==================================
Set compiler and options:
export CC=clang
export CFLAGS="-g -fsanitize=fuzzer-no-link,address,undefined \
-fno-sanitize-recover=all \
-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION"
Build libxml2 with instrumentation:
./configure --without-python
make
Run fuzzers:
make -C fuzz fuzz-xml