diff mbox series

[FFmpeg-devel] fate/integer.c: Connect test to fuzzer

Message ID 20210515163817.112623-1-vedaa@riseup.net
State Superseded
Headers show
Series [FFmpeg-devel] fate/integer.c: Connect test to fuzzer | expand

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Commit Message

Vedaa May 15, 2021, 4:38 p.m. UTC
Hi,

Apologies for the trivial mistakes. I have fixed them in this patch.
I have also added simple checks for overflow and underflow. Would this
be sufficient or should I reduce the bits I read from the fuzzer?
I will also submit a pull request to oss-fuzz as soon as this patch is
applied. :)

---
 Makefile                  |  2 ++
 libavutil/tests/integer.c | 21 ++----------------
 libavutil/tests/integer.h | 45 +++++++++++++++++++++++++++++++++++++++
 tools/Makefile            |  3 +++
 tools/target_int_fuzzer.c | 39 +++++++++++++++++++++++++++++++++
 5 files changed, 91 insertions(+), 19 deletions(-)
 create mode 100644 libavutil/tests/integer.h
 create mode 100644 tools/target_int_fuzzer.c

Comments

Michael Niedermayer May 16, 2021, 2:53 p.m. UTC | #1
On Sat, May 15, 2021 at 10:08:17PM +0530, Vedaa wrote:
> Hi,
> 
> Apologies for the trivial mistakes. I have fixed them in this patch.
> I have also added simple checks for overflow and underflow. Would this
> be sufficient or should I reduce the bits I read from the fuzzer?

its ok but theres a minor issue remaining


> I will also submit a pull request to oss-fuzz as soon as this patch is
> applied. :)

ok

[...]

> +int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
> +
> +int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
> +    if (size < 2 * sizeof(int64_t))
> +        return 1;
> +

> +    int64_t a,b,pdt;

This would produce a compiler warning 


> +    a = AV_RB64(data);
> +    b = AV_RB64(data + sizeof(int64_t));

> +    pdt = a * b;

Signed integer overflow is undefined behavior in C


> +    if ((b > 0 && a < INT64_MAX - b && a > INT64_MIN + b ) ||
> +        (b < 0 && a > INT64_MIN - b && a < INT64_MAX + b) &&
> +        pdt/b == a)
> +        TestInteger(a,b);
> +    return 0;
> +}

[...]
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 7e9d8b08c3..92fe8cac65 100644
--- a/Makefile
+++ b/Makefile
@@ -62,6 +62,8 @@  tools/target_dem_fuzzer$(EXESUF): tools/target_dem_fuzzer.o $(FF_DEP_LIBS)
 tools/target_io_dem_fuzzer$(EXESUF): tools/target_io_dem_fuzzer.o $(FF_DEP_LIBS)
 	$(LD) $(LDFLAGS) $(LDEXEFLAGS) $(LD_O) $^ $(ELIBS) $(FF_EXTRALIBS) $(LIBFUZZER_PATH)
 
+tools/target_int_fuzzer$(EXESUF): tools/target_int_fuzzer.o $(FF_DEP_LIBS)
+	$(LD) $(LDFLAGS) $(LDEXEFLAGS) $(LD_O) $^ $(ELIBS) $(FF_EXTRALIBS) $(LIBFUZZER_PATH)
 
 tools/enum_options$(EXESUF): ELIBS = $(FF_EXTRALIBS)
 tools/enum_options$(EXESUF): $(FF_DEP_LIBS)
diff --git a/libavutil/tests/integer.c b/libavutil/tests/integer.c
index d2c8f2a903..02e1d9219c 100644
--- a/libavutil/tests/integer.c
+++ b/libavutil/tests/integer.c
@@ -18,31 +18,14 @@ 
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include <stdint.h>
-
-#include "libavutil/avassert.h"
-#include "libavutil/integer.h"
-#include "libavutil/intmath.h"
+#include "libavutil/tests/integer.h"
 
 int main(void){
     int64_t a,b;
 
     for(a=7; a<256*256*256; a+=13215){
         for(b=3; b<256*256*256; b+=27118){
-            AVInteger ai= av_int2i(a);
-            AVInteger bi= av_int2i(b);
-
-            av_assert0(av_i2int(ai) == a);
-            av_assert0(av_i2int(bi) == b);
-            av_assert0(av_i2int(av_add_i(ai,bi)) == a+b);
-            av_assert0(av_i2int(av_sub_i(ai,bi)) == a-b);
-            av_assert0(av_i2int(av_mul_i(ai,bi)) == a*b);
-            av_assert0(av_i2int(av_shr_i(ai, 9)) == a>>9);
-            av_assert0(av_i2int(av_shr_i(ai,-9)) == a<<9);
-            av_assert0(av_i2int(av_shr_i(ai, 17)) == a>>17);
-            av_assert0(av_i2int(av_shr_i(ai,-17)) == a<<17);
-            av_assert0(av_log2_i(ai) == av_log2(a));
-            av_assert0(av_i2int(av_div_i(ai,bi)) == a/b);
+            TestInteger(a,b);
         }
     }
     return 0;
diff --git a/libavutil/tests/integer.h b/libavutil/tests/integer.h
new file mode 100644
index 0000000000..1e28c29787
--- /dev/null
+++ b/libavutil/tests/integer.h
@@ -0,0 +1,45 @@ 
+/*
+ * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#ifndef AVUTIL_TESTS_INTEGER_H
+#define AVUTIL_TESTS_INTEGER_H
+
+#include <stdint.h>
+#include "libavutil/avassert.h"
+#include "libavutil/integer.h"
+#include "libavutil/intmath.h"
+
+static inline void TestInteger(int64_t a, int64_t b)
+{
+        AVInteger ai= av_int2i(a);
+        AVInteger bi= av_int2i(b);
+
+        av_assert0(av_i2int(ai) == a);
+        av_assert0(av_i2int(bi) == b);
+        av_assert0(av_i2int(av_add_i(ai,bi)) == a+b);
+        av_assert0(av_i2int(av_sub_i(ai,bi)) == a-b);
+        av_assert0(av_i2int(av_mul_i(ai,bi)) == a*b);
+        av_assert0(av_i2int(av_shr_i(ai, 9)) == a>>9);
+        av_assert0(av_i2int(av_shr_i(ai,-9)) == a<<9);
+        av_assert0(av_i2int(av_shr_i(ai, 17)) == a>>17);
+        av_assert0(av_i2int(av_shr_i(ai,-17)) == a<<17);
+        av_assert0(av_log2_i(ai) == av_log2(a));
+        av_assert0(av_i2int(av_div_i(ai,bi)) == a/b);
+}
+#endif /* AVUTIL_TESTS_INTEGER_H */
diff --git a/tools/Makefile b/tools/Makefile
index 82baa8eadb..fde7f08984 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -17,6 +17,9 @@  tools/target_dem_fuzzer.o: tools/target_dem_fuzzer.c
 tools/target_io_dem_fuzzer.o: tools/target_dem_fuzzer.c
 	$(COMPILE_C) -DIO_FLAT=0
 
+tools/target_int_fuzzer.o: tools/target_int_fuzzer.c
+	$(COMPILE_C)
+
 OUTDIRS += tools
 
 clean::
diff --git a/tools/target_int_fuzzer.c b/tools/target_int_fuzzer.c
new file mode 100644
index 0000000000..e3f72d3356
--- /dev/null
+++ b/tools/target_int_fuzzer.c
@@ -0,0 +1,39 @@ 
+/*
+ * Copyright (c) 2021 Vedaa <vedaa@riseup.net>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/tests/integer.h"
+#include "libavutil/intreadwrite.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    if (size < 2 * sizeof(int64_t))
+        return 1;
+
+    int64_t a,b,pdt;
+    a = AV_RB64(data);
+    b = AV_RB64(data + sizeof(int64_t));
+    pdt = a * b;
+    if ((b > 0 && a < INT64_MAX - b && a > INT64_MIN + b ) ||
+        (b < 0 && a > INT64_MIN - b && a < INT64_MAX + b) &&
+        pdt/b == a)
+        TestInteger(a,b);
+    return 0;
+}