diff options
Diffstat (limited to 'tests')
| -rw-r--r-- | tests/Makefile.am | 1 | ||||
| -rw-r--r-- | tests/ossfuzz/Makefile | 7 | ||||
| -rw-r--r-- | tests/ossfuzz/config/fuzz.dict | 2 | ||||
| -rw-r--r-- | tests/ossfuzz/config/fuzz.options | 2 | ||||
| -rw-r--r-- | tests/ossfuzz/fuzz.c | 82 |
5 files changed, 94 insertions, 0 deletions
diff --git a/tests/Makefile.am b/tests/Makefile.am index 86084e17..4116b81a 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -7,6 +7,7 @@ EXTRA_DIST = \ files \ + ossfuzz \ tests.h \ test_files.sh \ test_compress.sh \ diff --git a/tests/ossfuzz/Makefile b/tests/ossfuzz/Makefile new file mode 100644 index 00000000..67ddbe5a --- /dev/null +++ b/tests/ossfuzz/Makefile @@ -0,0 +1,7 @@ +fuzz: fuzz.c + $(CC) $(CFLAGS) -c fuzz.c -I ../../src/liblzma/api/ + $(CXX) $(CXXFLAGS) -lFuzzingEngine fuzz.o -o $(OUT)/fuzz \ + ../../src/liblzma/.libs/liblzma.a + +clean: + rm -f *.o diff --git a/tests/ossfuzz/config/fuzz.dict b/tests/ossfuzz/config/fuzz.dict new file mode 100644 index 00000000..932d67c2 --- /dev/null +++ b/tests/ossfuzz/config/fuzz.dict @@ -0,0 +1,2 @@ +"\xFD7zXZ\x00" +"YZ" diff --git a/tests/ossfuzz/config/fuzz.options b/tests/ossfuzz/config/fuzz.options new file mode 100644 index 00000000..d59dfc13 --- /dev/null +++ b/tests/ossfuzz/config/fuzz.options @@ -0,0 +1,2 @@ +[libfuzzer] +dict = fuzz.dict diff --git a/tests/ossfuzz/fuzz.c b/tests/ossfuzz/fuzz.c new file mode 100644 index 00000000..6d899302 --- /dev/null +++ b/tests/ossfuzz/fuzz.c @@ -0,0 +1,82 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file fuzz.c +/// \brief Fuzz test program for liblzma +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include <inttypes.h> +#include <stdlib.h> +#include <stdio.h> +#include "lzma.h" + + +// Output buffer for decompressed data. This is write only; nothing cares +// about the actual data written here. +static uint8_t outbuf[4096]; + + +extern int +LLVMFuzzerTestOneInput(const uint8_t *inbuf, size_t inbuf_size) +{ + // Some header values can make liblzma allocate a lot of RAM + // (up to about 4 GiB with liblzma 5.2.x). We set a limit here to + // prevent extreme allocations when fuzzing. + const uint64_t memlimit = 300 << 20; // 300 MiB + + // Initialize a .xz decoder using the above memory usage limit. + // Enable support for concatenated .xz files which is used when + // decompressing regular .xz files (instead of data embedded inside + // some other file format). Integrity checks on the uncompressed + // data are ignored to make fuzzing more effective (incorrect check + // values won't prevent the decoder from processing more input). + // + // The flag LZMA_IGNORE_CHECK doesn't disable verification of header + // CRC32 values. Those checks are disabled when liblzma is built + // with the #define FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION. + lzma_stream strm = LZMA_STREAM_INIT; + lzma_ret ret = lzma_stream_decoder(&strm, memlimit, + LZMA_CONCATENATED | LZMA_IGNORE_CHECK); + if (ret != LZMA_OK) { + // This should never happen unless the system has + // no free memory or address space to allow the small + // allocations that the initialization requires. + fprintf(stderr, "lzma_stream_decoder() failed (%d)\n", ret); + abort(); + } + + // Give the whole input buffer at once to liblzma. + // Output buffer isn't initialized as liblzma only writes to it. + strm.next_in = inbuf; + strm.avail_in = inbuf_size; + strm.next_out = outbuf; + strm.avail_out = sizeof(outbuf); + + while ((ret = lzma_code(&strm, LZMA_FINISH)) == LZMA_OK) { + if (strm.avail_out == 0) { + // outbuf became full. We don't care about the + // uncompressed data there, so we simply reuse + // the outbuf and overwrite the old data. + strm.next_out = outbuf; + strm.avail_out = sizeof(outbuf); + } + } + + // LZMA_PROG_ERROR should never happen as long as the code calling + // the liblzma functions is correct. Thus LZMA_PROG_ERROR is a sign + // of a bug in either this function or in liblzma. + if (ret == LZMA_PROG_ERROR) { + fprintf(stderr, "lzma_code() returned LZMA_PROG_ERROR\n"); + abort(); + } + + // Free the allocated memory. + lzma_end(&strm); + + return 0; +} |