ref: da9e67ce3c4e4bc96f46aac22bbb385031482225
parent: a4585285ed1dda87f96b4ff0531ecccc224486a2
parent: 45dbe94ee01491444a1001c62e1d27981bed51f3
author: Yaowu Xu <yaowu@google.com>
date: Tue Oct 15 10:28:08 EDT 2013
Merge "Add clamp to prevent out of bound access"
--- a/vp9/decoder/vp9_dsubexp.c
+++ b/vp9/decoder/vp9_dsubexp.c
@@ -48,8 +48,6 @@
static int inv_remap_prob(int v, int m) { static int inv_map_table[MAX_PROB - 1] = {- // generated by:
- // inv_map_table[j] = merge_index(j, MAX_PROB - 1, MODULUS_PARAM);
6, 19, 32, 45, 58, 71, 84, 97, 110, 123, 136, 149, 162, 175, 188,
201, 214, 227, 240, 253, 0, 1, 2, 3, 4, 5, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26,
@@ -66,9 +64,11 @@
190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 202, 203, 204, 205,
206, 207, 208, 209, 210, 211, 212, 213, 215, 216, 217, 218, 219, 220, 221,
222, 223, 224, 225, 226, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237,
- 238, 239, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252,
+ 238, 239, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252
};
- // v = merge_index(v, MAX_PROBS - 1, MODULUS_PARAM);
+ // The clamp is not necessary for conforming VP9 stream, it is added to
+ // prevent out of bound access for bad input data
+ v = clamp(v, 0, 253);
v = inv_map_table[v];
m--;
if ((m << 1) <= MAX_PROB) {