CVE-2023-53585

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

bpf: reject unhashed sockets in bpf_sk_assign

The semantics for bpf_sk_assign are as follows:

sk = some_lookup_func()

bpf_sk_assign(skb, sk)

bpf_sk_release(sk)

That is, the sk is not consumed by bpf_sk_assign. The function

therefore needs to make sure that sk lives long enough to be

consumed from __inet_lookup_skb. The path through the stack for a

TCPv4 packet is roughly:

netif_receive_skb_core: takes RCU read lock

__netif_receive_skb_core:

sch_handle_ingress:

tcf_classify:

bpf_sk_assign()

deliver_ptype_list_skb:

deliver_skb:

ip_packet_type->func == ip_rcv:

ip_rcv_core:

ip_rcv_finish_core:

dst_input:

ip_local_deliver:

ip_local_deliver_finish:

ip_protocol_deliver_rcu:

tcp_v4_rcv:

__inet_lookup_skb:

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References