[FFmpeg-devel] [PATCH 1/3] ffmdec: reset packet_end in case of failure

[Andreas Cadhalpun]

This fixes segmentation faults caused by passing a packet_ptr of NULL to
memcpy.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
---
 libavformat/ffmdec.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libavformat/ffmdec.c b/libavformat/ffmdec.c
index 9fe4155..7b2d0d7 100644
--- a/libavformat/ffmdec.c
+++ b/libavformat/ffmdec.c
@@ -123,8 +123,10 @@ static int ffm_read_data(AVFormatContext *s,
             frame_offset = avio_rb16(pb);
             avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
             ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
-            if (ffm->packet_end < ffm->packet || frame_offset < 0)
+            if (ffm->packet_end < ffm->packet || frame_offset < 0) {
+                ffm->packet_end = ffm->packet_ptr;
                 return -1;
+            }
             /* if first packet or resynchronization packet, we must
                handle it specifically */
             if (ffm->first_packet || (frame_offset & 0x8000)) {
@@ -140,8 +142,10 @@ static int ffm_read_data(AVFormatContext *s,
                     return 0;
                 }
                 ffm->first_packet = 0;
-                if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
+                if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE) {
+                    ffm->packet_end = ffm->packet_ptr;
                     return -1;
+                }
                 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
                 if (!header)
                     break;
-- 
2.6.4