ea: check chunk_size for validity.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit 273e6af47b38391f2bcc157cca0423fe7fcbf55c)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 6a86b705e1d4b72f0dddfbe23ad3eed9947001d5)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>

diff --git a/libavformat/electronicarts.c b/libavformat/electronicarts.c
index 06689dd..0a6cdd5 100644 (file)
--- a/libavformat/electronicarts.c
+++ b/libavformat/electronicarts.c
@@ -468,12 +468,17 @@ static int ea_read_packet(AVFormatContext *s,
 
     while (!packet_read) {
         chunk_type = avio_rl32(pb);
-        chunk_size = (ea->big_endian ? avio_rb32(pb) : avio_rl32(pb)) - 8;
+        chunk_size = ea->big_endian ? avio_rb32(pb) : avio_rl32(pb);
+        if (chunk_size <= 8)
+            return AVERROR_INVALIDDATA;
+        chunk_size -= 8;
 
         switch (chunk_type) {
         /* audio data */
         case ISNh_TAG:
             /* header chunk also contains data; skip over the header portion*/
+            if (chunk_size < 32)
+                return AVERROR_INVALIDDATA;
             avio_skip(pb, 32);
             chunk_size -= 32;
         case ISNd_TAG: