[FFmpeg-devel] [PATCH 1/2] avformat/aiffdec: avoid integer overflow in get_meta()

[FFmpeg-devel] [PATCH 1/2] avformat/aiffdec: avoid integer overflow in get_meta()

[Michael Niedermayer]

Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
Fixes: 45891/clusterfuzz-testcase-minimized-ffmpeg_dem_AIFF_fuzzer-6159183893889024

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/aiffdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/aiffdec.c b/libavformat/aiffdec.c
index 3634bb4960..5236cc2807 100644
--- a/libavformat/aiffdec.c
+++ b/libavformat/aiffdec.c
@@ -72,7 +72,7 @@ static int get_tag(AVIOContext *pb, uint32_t * tag)
 /* Metadata string read */
 static void get_meta(AVFormatContext *s, const char *key, int size)
 {
-    uint8_t *str = av_malloc(size+1);
+    uint8_t *str = av_malloc(size+1U);
 
     if (str) {
         int res = avio_read(s->pb, str, size);
-- 
2.17.1

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[FFmpeg-devel] [PATCH 2/2] avformat/aiffdec: cleanup size handling for extreem cases

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/aiffdec.c | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/libavformat/aiffdec.c b/libavformat/aiffdec.c
index 5236cc2807..2bdcd1362b 100644
--- a/libavformat/aiffdec.c
+++ b/libavformat/aiffdec.c
@@ -53,9 +53,9 @@ static enum AVCodecID aiff_codec_get_id(int bps)
 }
 
 /* returns the size of the found tag */
-static int get_tag(AVIOContext *pb, uint32_t * tag)
+static int64_t get_tag(AVIOContext *pb, uint32_t * tag)
 {
-    int size;
+    int64_t size;
 
     if (avio_feof(pb))
         return AVERROR(EIO);
@@ -63,16 +63,16 @@ static int get_tag(AVIOContext *pb, uint32_t * tag)
     *tag = avio_rl32(pb);
     size = avio_rb32(pb);
 
-    if (size < 0)
-        size = 0x7fffffff;
-
     return size;
 }
 
 /* Metadata string read */
-static void get_meta(AVFormatContext *s, const char *key, int size)
+static void get_meta(AVFormatContext *s, const char *key, int64_t size)
 {
-    uint8_t *str = av_malloc(size+1U);
+    uint8_t *str = NULL;
+
+    if (size < SIZE_MAX)
+        str = av_malloc(size+1);
 
     if (str) {
         int res = avio_read(s->pb, str, size);
@@ -89,7 +89,7 @@ static void get_meta(AVFormatContext *s, const char *key, int size)
 }
 
 /* Returns the number of sound data frames or negative on error */
-static int get_aiff_header(AVFormatContext *s, int size,
+static int get_aiff_header(AVFormatContext *s, int64_t size,
                                     unsigned version)
 {
     AVIOContext *pb        = s->pb;
@@ -101,9 +101,6 @@ static int get_aiff_header(AVFormatContext *s, int size,
     unsigned int num_frames;
     int channels;
 
-    if (size == INT_MAX)
-        return AVERROR_INVALIDDATA;
-
     if (size & 1)
         size++;
     par->codec_type = AVMEDIA_TYPE_AUDIO;
@@ -215,7 +212,8 @@ static int aiff_probe(const AVProbeData *p)
 /* aiff input */
 static int aiff_read_header(AVFormatContext *s)
 {
-    int ret, size, filesize;
+    int ret;
+    int64_t filesize, size;
     int64_t offset = 0, position;
     uint32_t tag;
     unsigned version = AIFF_C_VERSION1;
@@ -226,7 +224,7 @@ static int aiff_read_header(AVFormatContext *s)
 
     /* check FORM header */
     filesize = get_tag(pb, &tag);
-    if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
+    if (filesize < 4 || tag != MKTAG('F', 'O', 'R', 'M'))
         return AVERROR_INVALIDDATA;
 
     /* AIFF data type */
@@ -253,10 +251,7 @@ static int aiff_read_header(AVFormatContext *s)
         if (size < 0)
             return size;
 
-        if (size >= 0x7fffffff - 8)
-            filesize = 0;
-        else
-            filesize -= size + 8;
+        filesize -= size + 8;
 
         switch (tag) {
         case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */
-- 
2.17.1

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Re: [FFmpeg-devel] [PATCH 1/2] avformat/aiffdec: avoid integer overflow in get_meta()

[Michael Niedermayer]

[-- Attachment #1.1: Type: text/plain, Size: 865 bytes --]

On Wed, Mar 23, 2022 at 03:05:02PM +0100, Michael Niedermayer wrote:
> Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
> Fixes: 45891/clusterfuzz-testcase-minimized-ffmpeg_dem_AIFF_fuzzer-6159183893889024
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavformat/aiffdec.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

will apply

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Dictatorship: All citizens are under surveillance, all their steps and
actions recorded, for the politicians to enforce control.
Democracy: All politicians are under surveillance, all their steps and
actions recorded, for the citizens to enforce control.

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Re: [FFmpeg-devel] [PATCH 2/2] avformat/aiffdec: cleanup size handling for extreem cases

[Michael Niedermayer]

[-- Attachment #1.1: Type: text/plain, Size: 523 bytes --]

On Wed, Mar 23, 2022 at 03:05:03PM +0100, Michael Niedermayer wrote:
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavformat/aiffdec.c | 29 ++++++++++++-----------------
>  1 file changed, 12 insertions(+), 17 deletions(-)

will apply


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In fact, the RIAA has been known to suggest that students drop out
of college or go to community college in order to be able to afford
settlements. -- The RIAA

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