fuzz: add fuzz_lzxpress_huffman_decompress

Most strings will not successfully decompress, which is OK. What we
care about of course is memory safety.

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Joseph Sutton <josephsutton@catalyst.net.nz>

diff --git a/lib/fuzzing/fuzz_lzxpress_huffman_decompress.c b/lib/fuzzing/fuzz_lzxpress_huffman_decompress.c
new file mode 100644 (file)
index 0000000..da3a101
--- /dev/null
+++ b/lib/fuzzing/fuzz_lzxpress_huffman_decompress.c
@@ -0,0 +1,48 @@
+/*
+   Fuzzing for lzxpress_decompress
+   Copyright (C) Michael Hanselmann 2019
+   Copyright (C) Douglas Bagnall 2022 <dbagnall@samba.org>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "fuzzing/fuzzing.h"
+#include "compression/lzxpress_huffman.h"
+
+int LLVMFuzzerInitialize(int *argc, char ***argv)
+{
+       return 0;
+}
+
+static uint8_t output[1024 * 1024] = {0};
+
+int LLVMFuzzerTestOneInput(uint8_t *buf, size_t len)
+{
+       size_t target_len;
+       if (len < 4) {
+               return 0;
+       }
+       /*
+        * An exact target length is required, which we store in the first 24
+        * bits.
+        */
+       target_len = MIN(sizeof(output), buf[0] | (buf[1] << 8) | (buf[2] << 16));
+       buf += 3;
+       len -= 3;
+
+       lzxpress_huffman_decompress(buf, len, output, target_len);
+
+       return 0;
+}

diff --git a/lib/fuzzing/wscript_build b/lib/fuzzing/wscript_build
index ca6c4f777a3d662d71c3fbb5b017212b8fa49649..600c827e31e8801c86025bd02d8f609f420552a7 100644 (file)
--- a/lib/fuzzing/wscript_build
+++ b/lib/fuzzing/wscript_build
@@ -57,6 +57,11 @@ bld.SAMBA_BINARY('fuzz_lzxpress_round_trip',
                  deps='fuzzing LZXPRESS afl-fuzz-main',
                  fuzzer=True)
 
+bld.SAMBA_BINARY('fuzz_lzxpress_huffman_decompress',
+                 source='fuzz_lzxpress_huffman_decompress.c',
+                 deps='fuzzing LZXPRESS afl-fuzz-main',
+                 fuzzer=True)
+
 bld.SAMBA_BINARY('fuzz_ldap_decode',
                  source='fuzz_ldap_decode.c',
                  deps='fuzzing cli-ldap afl-fuzz-main',