vp8 boolreader: ignore invalid input

Do basic initialization even when the result will not be used. BUG=chromium:1026961

Johann committed 6 years ago

Commit 80e56661 parent 89375f01 file · +5 −1Browse files

Unified · Split

vp8/decoder/dboolhuff.c+5−1

@@ -15,7 +15,11 @@ · 14 unmodified lines
15	15	int vp8dx_start_decode(BOOL_DECODER br, const unsigned char source,
16	16	unsigned int source_sz, vpx_decrypt_cb decrypt_cb,
17	17	void *decrypt_state) {
18		− br->user_buffer_end = source + source_sz;
	18	+ // To simplify calling code this fuction can be called with \|source\| == null
	19	+ // and \|source_sz\| == 0. This and vp8dx_bool_decoder_fill() are essentially
	20	+ // no-ops in this case.
	21	+ // Work around a ubsan warning with a ternary to avoid adding 0 to null.
	22	+ br->user_buffer_end = source ? source + source_sz : source;
19	23	br->user_buffer = source;
20	24	br->value = 0;
21	25	br->count = -8;