CVE-2026-93174

/// Technical description

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

bpf: Copy per-CPU map value padding in copy_map_value_long()

In kernel, per-CPU map elements are stored with

round_up(map->value_size, 8) bytes. On UAPI lookup paths, it copies the

rounded size for each CPU into a temporary buffer.

However, copy_map_value_long() passes 'map->value_size' to

bpf_obj_memcpy(). When the map has special fields, bpf_obj_memcpy() copies

around those fields with memcpy(), and does not copy the tail padding

between 'map->value_size' and round_up(map->value_size, 8).

The temporary UAPI lookup buffers are allocated without __GFP_ZERO. As a

result, when the per-CPU map's value size is not equal to

round_up(map->value_size, 8), UAPI LOOKUP_ELEM and its variants can return

stale heap contents from that padding to user space. The same issue

applies to bpf_iter for per-CPU maps.

Pass round_up(map->value_size, 8) to bpf_obj_memcpy() from

copy_map_value_long(), so per-CPU maps both with and without

/// 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