CVE-2023-54283

/// Technical description

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

bpf: Address KCSAN report on bpf_lru_list

KCSAN reported a data-race when accessing node->ref.

Although node->ref does not have to be accurate,

take this chance to use a more common READ_ONCE() and WRITE_ONCE()

pattern instead of data_race().

There is an existing bpf_lru_node_is_ref() and bpf_lru_node_set_ref().

This patch also adds bpf_lru_node_clear_ref() to do the

WRITE_ONCE(node->ref, 0) also.

==================================================================

BUG: KCSAN: data-race in __bpf_lru_list_rotate / __htab_lru_percpu_map_update_elem

write to 0xffff888137038deb of 1 bytes by task 11240 on cpu 1:

__bpf_lru_node_move kernel/bpf/bpf_lru_list.c:113 [inline]

__bpf_lru_list_rotate_active kernel/bpf/bpf_lru_list.c:149 [inline]

__bpf_lru_list_rotate+0x1bf/0x750 kernel/bpf/bpf_lru_list.c:240

bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:329 [inline]

bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:44

/// 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