CVE-2026-90269

/// Technical description

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

bpf: Reject load-acquire from pointers requiring fault protection

A BPF_LOAD_ACQ is not rewritten to a BPF_PROBE_MEM load by the verifier,

unlike a regular BPF_LDX, so the JIT emits a plain load with no exception

table entry and a fault panics the kernel instead of being handled.

Reject the source pointer types that a BPF_LDX would have had that fault

protection applied to, i.e. the ones bpf_convert_ctx_accesses() turns

into BPF_PROBE_MEM: a bare PTR_TO_BTF_ID, PTR_TO_BTF_ID | PTR_UNTRUSTED,

PTR_TO_BTF_ID | MEM_ALLOC | PTR_UNTRUSTED and PTR_TO_MEM | MEM_RDONLY |

PTR_UNTRUSTED.

This is reachable e.g. by loading ->mm out of a trusted task_struct

yields an untrusted pointer to mm_struct, and it is NULL for a kernel

thread:

[...]

SEC("tp_btf/sched_switch")

int BPF_PROG(demo, bool preempt, struct task_struct *prev,

struct task_struct *next)

{

struct mm_struct *mm = next->mm; /* untrusted *

/// 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