diff options
| author | Gaurav Narula <gnarula94@gmail.com> | 2011-12-13 23:11:37 +0530 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2011-12-13 20:08:15 +0200 |
| commit | a99273ebf328658c183c2d267f1c2b8bfac58bb3 (patch) | |
| tree | f5668a7e645066765f1dc6f9c6f90ff7f46e3052 /libavcodec/ulti.c | |
| parent | 4badb386cee42569e2e1a1c6981a33c065ebf2de (diff) | |
ulti: Fix invalid reads
Signed-off-by: Martin Storsjö <martin@martin.st>
Diffstat (limited to 'libavcodec/ulti.c')
| -rw-r--r-- | libavcodec/ulti.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/libavcodec/ulti.c b/libavcodec/ulti.c index a2802f73a9..52092b5309 100644 --- a/libavcodec/ulti.c +++ b/libavcodec/ulti.c @@ -40,6 +40,14 @@ typedef struct UltimotionDecodeContext { const uint8_t *ulti_codebook; } UltimotionDecodeContext; +#define CHECK_OVERREAD_SIZE(size) \ + do { \ + if (buf_end - buf < (size)) { \ + av_log(avctx, AV_LOG_ERROR, "Insufficient data\n"); \ + return AVERROR_INVALIDDATA; \ + } \ + } while(0) + static av_cold int ulti_decode_init(AVCodecContext *avctx) { UltimotionDecodeContext *s = avctx->priv_data; @@ -223,6 +231,7 @@ static int ulti_decode_frame(AVCodecContext *avctx, int i; int skip; int tmp; + const uint8_t *buf_end = buf + buf_size; s->frame.reference = 1; s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; @@ -236,10 +245,12 @@ static int ulti_decode_frame(AVCodecContext *avctx, if(blocks >= s->blocks || y >= s->height) break;//all blocks decoded + CHECK_OVERREAD_SIZE(1); idx = *buf++; if((idx & 0xF8) == 0x70) { switch(idx) { case 0x70: //change modifier + CHECK_OVERREAD_SIZE(1); modifier = *buf++; if(modifier>1) av_log(avctx, AV_LOG_INFO, "warning: modifier must be 0 or 1, got %i\n", modifier); @@ -254,6 +265,7 @@ static int ulti_decode_frame(AVCodecContext *avctx, done = 1; break; case 0x74: //skip some blocks + CHECK_OVERREAD_SIZE(1); skip = *buf++; if ((blocks + skip) >= s->blocks) break; @@ -280,19 +292,24 @@ static int ulti_decode_frame(AVCodecContext *avctx, chroma = 0; } else { cf = 0; - if (idx) + if (idx) { + CHECK_OVERREAD_SIZE(1); chroma = *buf++; + } } for (i = 0; i < 4; i++) { // for every subblock code = (idx >> (6 - i*2)) & 3; //extract 2 bits if(!code) //skip subblock continue; - if(cf) + if(cf) { + CHECK_OVERREAD_SIZE(1); chroma = *buf++; + } tx = x + block_coords[i * 2]; ty = y + block_coords[(i * 2) + 1]; switch(code) { case 1: + CHECK_OVERREAD_SIZE(1); tmp = *buf++; angle = angle_by_index[(tmp >> 6) & 0x3]; @@ -313,6 +330,7 @@ static int ulti_decode_frame(AVCodecContext *avctx, case 2: if (modifier) { // unpack four luma samples + CHECK_OVERREAD_SIZE(3); tmp = bytestream_get_be24(&buf); Y[0] = (tmp >> 18) & 0x3F; @@ -321,6 +339,7 @@ static int ulti_decode_frame(AVCodecContext *avctx, Y[3] = tmp & 0x3F; angle = 16; } else { // retrieve luma samples from codebook + CHECK_OVERREAD_SIZE(2); tmp = bytestream_get_be16(&buf); angle = (tmp >> 12) & 0xF; @@ -337,6 +356,8 @@ static int ulti_decode_frame(AVCodecContext *avctx, if (modifier) { // all 16 luma samples uint8_t Luma[16]; + CHECK_OVERREAD_SIZE(12); + tmp = bytestream_get_be24(&buf); Luma[0] = (tmp >> 18) & 0x3F; Luma[1] = (tmp >> 12) & 0x3F; @@ -363,6 +384,7 @@ static int ulti_decode_frame(AVCodecContext *avctx, ulti_convert_yuv(&s->frame, tx, ty, Luma, chroma); } else { + CHECK_OVERREAD_SIZE(4); tmp = *buf++; if(tmp & 0x80) { angle = (tmp >> 4) & 0x7; |