CVE-2026-68337EPSS p5.2%
CVE-2026-68337CVE-2026-68337
Description
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_ne
Scoring
| EPSS | 0.15% probability of exploitation · percentile 5.2% · 2026-08-11T12:00:17Z |
| Last modified | 2026-08-10 |