Multiple integer underflows in the x25_parse_facilities function in net/x25/x25_facilities.c in the Linux kernel before 2.6.36.2 allow remote attackers to cause a denial of service (system crash) via malformed X.25 (1) X25_FAC_CLASS_A, (2) X25_FAC_CLASS_B, (3) X25_FAC_CLASS_C, or (4) X25_FAC_CLASS_D facility data, a different vulnerability than CVE-2010-3873.