CVE 2011-0473
Google Chrome before 8.0.552.237 and Chrome OS before 8.0.552.344 do not properly handle Cascading Style Sheets (CSS) token sequences in conjunction with CANVAS elements, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via unknown vectors that lead to a "stale pointer."
See the 
CVE page on Mitre.org
for more details.
