libvorbis -- two vulnerabilities

Two vulnerabilities were fixed in the upstream repository:

• The bark_noise_hybridmp function allows remote attackers to cause a denial of service (out-of-bounds access and application crash) or possibly have unspecified other impact via a crafted file.
• mapping0_forward does not validate the number of channels, which allows remote attackers to cause a denial of service (heap-based buffer overflow or over-read) or possibly have unspecified other impact via a crafted file.