From 30b996d443aeb105d0017b06ce590c55a0b2f9f4 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 15 Dec 2011 04:42:13 +0100 Subject: [PATCH] flicvideo: input buffer pointer checks. Signed-off-by: Michael Niedermayer --- libavcodec/flicvideo.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/libavcodec/flicvideo.c b/libavcodec/flicvideo.c index 28009cddba..dded6f5293 100644 --- a/libavcodec/flicvideo.c +++ b/libavcodec/flicvideo.c @@ -499,16 +499,27 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, stream_ptr += 6; /* skip the magic number */ num_chunks = AV_RL16(&buf[stream_ptr]); stream_ptr += 10; /* skip padding */ + if (frame_size > buf_size) + frame_size = buf_size; frame_size -= 16; /* iterate through the chunks */ while ((frame_size > 0) && (num_chunks > 0)) { + int stream_ptr_after_chunk; chunk_size = AV_RL32(&buf[stream_ptr]); + if (chunk_size > frame_size) { + av_log(avctx, AV_LOG_WARNING, + "Invalid chunk_size = %u > frame_size = %u\n", chunk_size, frame_size); + chunk_size = frame_size; + } + stream_ptr_after_chunk = stream_ptr + chunk_size; + stream_ptr += 4; chunk_type = AV_RL16(&buf[stream_ptr]); stream_ptr += 2; + switch (chunk_type) { case FLI_256_COLOR: case FLI_COLOR: @@ -525,6 +536,8 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, compressed_lines = AV_RL16(&buf[stream_ptr]); stream_ptr += 2; while (compressed_lines > 0) { + if (stream_ptr + 2 > stream_ptr_after_chunk) + break; line_packets = AV_RL16(&buf[stream_ptr]); stream_ptr += 2; if (line_packets < 0) { @@ -537,6 +550,8 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, pixel_countdown = s->avctx->width; for (i = 0; i < line_packets; i++) { /* account for the skip bytes */ + if (stream_ptr + 2 > stream_ptr_after_chunk) + break; pixel_skip = buf[stream_ptr++]; pixel_ptr += (pixel_skip*2); /* Pixel is 2 bytes wide */ pixel_countdown -= pixel_skip; @@ -551,6 +566,8 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, pixel_ptr += 2; } } else { + if (stream_ptr + 2*byte_run > stream_ptr_after_chunk) + break; CHECK_PIXEL_PTR(2 * byte_run); for (j = 0; j < byte_run; j++, pixel_countdown--) { *((signed short*)(&pixels[pixel_ptr])) = AV_RL16(&buf[stream_ptr]); @@ -586,6 +603,8 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, pixel_countdown = (s->avctx->width * 2); while (pixel_countdown > 0) { + if (stream_ptr + 1 > stream_ptr_after_chunk) + break; byte_run = (signed char)(buf[stream_ptr++]); if (byte_run > 0) { palette_idx1 = buf[stream_ptr++]; @@ -599,6 +618,8 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, } } else { /* copy bytes if byte_run < 0 */ byte_run = -byte_run; + if (stream_ptr + byte_run > stream_ptr_after_chunk) + break; CHECK_PIXEL_PTR(byte_run); for (j = 0; j < byte_run; j++) { palette_idx1 = buf[stream_ptr++]; @@ -638,6 +659,8 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, pixel_countdown = s->avctx->width; /* Width is in pixels, not bytes */ while (pixel_countdown > 0) { + if (stream_ptr + 1 > stream_ptr_after_chunk) + break; byte_run = (signed char)(buf[stream_ptr++]); if (byte_run > 0) { pixel = AV_RL16(&buf[stream_ptr]); @@ -653,6 +676,8 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx, } } else { /* copy pixels if byte_run < 0 */ byte_run = -byte_run; + if (stream_ptr + 2 * byte_run > stream_ptr_after_chunk) + break; CHECK_PIXEL_PTR(2 * byte_run); for (j = 0; j < byte_run; j++) { *((signed short*)(&pixels[pixel_ptr])) = AV_RL16(&buf[stream_ptr]);