Re: [PATCH] sbc: Fix off-by-one error in index check when unpacking frame

[Per Waagø <pwaago@xxxxxxxxx>]

The problem can be demonstrated with the program below. Valgrind will 
fail when running this program for values of short_packet_size from 12 
through 113.
--
#include <sbc/sbc.h>

#include <stdlib.h>
#include <string.h>

static void encode_and_truncate_frame(uint8_t * dest, size_t dest_size)
{
    sbc_t enc;
    sbc_init(&enc, 0);
    enc.frequency = SBC_FREQ_48000;
    enc.blocks = SBC_BLK_16;
    enc.subbands = SBC_SB_8;
    enc.mode = SBC_MODE_STEREO;
    enc.allocation = SBC_AM_LOUDNESS;
    enc.bitpool = 51;
    enc.endian = SBC_LE;

    const size_t input_frame_size = sbc_get_codesize(&enc);
    const size_t output_frame_size = sbc_get_frame_length(&enc);
    uint8_t * input_frame = calloc(1, input_frame_size);
    uint8_t * output_frame = calloc(1, input_frame_size);

    ssize_t produced;
    sbc_encode(&enc, input_frame, input_frame_size,
        output_frame, output_frame_size,
        &produced);

    memcpy(dest, output_frame, dest_size);

    free(input_frame);
    free(output_frame);
    sbc_finish(&enc);
}

int main(int argc, char * argv[])
{
    const size_t short_packet_size = 12;
    uint8_t * short_packet = malloc(short_packet_size);
    encode_and_truncate_frame(short_packet, short_packet_size);

    sbc_t dec;
    sbc_init(&dec, 0);

    sbc_parse(&dec, short_packet, short_packet_size);

    sbc_finish(&dec);
    free(short_packet);
    return 0;
}