NULL Pointer Dereference Affecting kernel-rt-64k-debug-modules package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.16% (6th percentile)

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  • Snyk IDSNYK-RHEL10-KERNELRT64KDEBUGMODULES-18639573
  • published12 Aug 2026
  • disclosed10 Aug 2026

Introduced: 10 Aug 2026

NewCVE-2026-68337  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-rt-64k-debug-modules.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-64k-debug-modules package and not the kernel-rt-64k-debug-modules package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

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

bpf: Reject redirect helpers without a bpf_net_context

The bpf_redirect*() helpers and skb_do_redirect() obtain the per-task bpf_redirect_info via bpf_net_ctx_get_ri(), which dereferences the current->bpf_net_context unconditionally. That context is established on the paths that run tc BPF such as sch_handle_{ingress,egress}(), except for the case where {cls,act}_bpf was attached to a proper qdisc. A program running from there reaches the NULL deref in two ways:

  • It calls bpf_redirect() directly, which dereferences the context at the top of the helper:

    tc qdisc add dev eth0 root handle 1: red limit 1MB min 10KB max 20KB
    avpkt 1000 burst 100 qevent early_drop block 10 tc filter add block 10 pref 1 bpf obj redirect.o

  • It simply returns TC_ACT_REDIRECT without helper call: tcf_qevent_handle() then dispatches to skb_do_redirect(), which dereferences the context

Rather than extending bpf_net_context management into the qdisc path, make the redirect helpers refuse to operate when no context exists, and have tcf_qevent_handle() drop a TC_ACT_REDIRECT verdict instead of calling skb_do_redirect(). Previous behaviour was a crash, so nothing regresses by not supporting it.

CVSS Base Scores

version 3.1