[FFmpeg-cvslog] avformat/paf: Check for EOF in read_table()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Oct 24 20:30:48 2020 +0200| [437b7302b09a04e0fbfcd594114b52c5c6d89d32] | committer: Michael Niedermayer

avformat/paf: Check for EOF in read_table()

Fixes: OOM
Fixes: 26528/clusterfuzz-testcase-minimized-ffmpeg_dem_PAF_fuzzer-5081929248145408
Fixes: 26584/clusterfuzz-testcase-minimized-ffmpeg_dem_PAF_fuzzer-5172661183053824

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=437b7302b09a04e0fbfcd594114b52c5c6d89d32
---

 libavformat/paf.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/libavformat/paf.c b/libavformat/paf.c
index a31d01502b..9587111643 100644
--- a/libavformat/paf.c
+++ b/libavformat/paf.c
@@ -75,14 +75,18 @@ static int read_close(AVFormatContext *s)
     return 0;
 }
 
-static void read_table(AVFormatContext *s, uint32_t *table, uint32_t count)
+static int read_table(AVFormatContext *s, uint32_t *table, uint32_t count)
 {
     int i;
 
-    for (i = 0; i < count; i++)
+    for (i = 0; i < count; i++) {
+        if (avio_feof(s->pb))
+            return AVERROR_INVALIDDATA;
         table[i] = avio_rl32(s->pb);
+    }
 
     avio_skip(s->pb, 4 * (FFALIGN(count, 512) - count));
+    return 0;
 }
 
 static int read_header(AVFormatContext *s)
@@ -171,9 +175,15 @@ static int read_header(AVFormatContext *s)
 
     avio_seek(pb, p->buffer_size, SEEK_SET);
 
-    read_table(s, p->blocks_count_table,  p->nb_frames);
-    read_table(s, p->frames_offset_table, p->nb_frames);
-    read_table(s, p->blocks_offset_table, p->frame_blks);
+    ret = read_table(s, p->blocks_count_table,  p->nb_frames);
+    if (ret < 0)
+        goto fail;
+    ret = read_table(s, p->frames_offset_table, p->nb_frames);
+    if (ret < 0)
+        goto fail;
+    ret = read_table(s, p->blocks_offset_table, p->frame_blks);
+    if (ret < 0)
+        goto fail;
 
     p->got_audio = 0;
     p->current_frame = 0;