From 1f0ab0b089e357da4ecfec4f105726bfc23af5a0 Mon Sep 17 00:00:00 2001 From: Harish Mahendrakar Date: Fri, 23 Dec 2016 15:29:14 +0530 Subject: [PATCH] DO NOT MERGE: Decoder: Fixes an out of bound write in bitstream buffer [this is for mnc-dev only, not any other mnc-*-dev flavors; there is a different patch for mnc-dr-dev, nyc-* and going forward] After emulation prevention, data is written as an int, so at least 3 additional bytes should be available. And since bitstream functions read 8 bytes ahead, 8 extra bytes should be available in the bitstream buffer. Bug: 33934721 Test: Ittiam testing, POC in the bug no longer fails Change-Id: I444ec6f85d01b0bade9f827e15c4b476779d6c69 --- decoder/ih264d_api.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/decoder/ih264d_api.c b/decoder/ih264d_api.c index 8d73fbe..aa1312b 100644 --- a/decoder/ih264d_api.c +++ b/decoder/ih264d_api.c @@ -2911,7 +2911,9 @@ WORD32 ih264d_video_decode(iv_obj_t *dec_hdl, void *pv_api_ip, void *pv_api_op) if(buflen == -1) buflen = 0; /* Ignore bytes beyond the allocated size of intermediate buffer */ - buflen = MIN(buflen, (WORD32)ps_dec->ps_mem_tab[MEM_REC_BITSBUF].u4_mem_size); + /* Since 8 bytes are read ahead, ensure 8 bytes are free at the + end of the buffer, which will be memset to 0 after emulation prevention */ + buflen = MIN(buflen, (WORD32)(ps_dec->ps_mem_tab[MEM_REC_BITSBUF].u4_mem_size - 8)); bytes_consumed = buflen + u4_length_of_start_code; ps_dec_op->u4_num_bytes_consumed += bytes_consumed;