The udp_queue_rcv_skb function in net/ipv4/udp.c in a certain Red Hat build of the Linux kernel 2.6.18 in Red Hat Enterprise Linux (RHEL) 5 allows attackers to cause a denial of service (deadlock and system hang) by sending UDP traffic to a socket that has a crafted socket filter, a related issue to CVE-2010-4158.

The sk_run_filter function in net/core/filter.c in the Linux kernel before 2.6.36.2 does not check whether a certain memory location has been initialized before executing a (1) BPF_S_LD_MEM or (2) BPF_S_LDX_MEM instruction, which allows local users to obtain potentially sensitive information from kernel stack memory via a crafted socket filter.