CVE-2025-68200: bpf: Add bpf_prog_run_data_pointers()

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-16 · updated 2026-10-14

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Add bpf_prog_run_data_pointers() syzbot found that cls_bpf_classify() is able to change tc_skb_cb(skb)->drop_reason triggering a warning in sk_skb_reason_drop(). WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 __sk_skb_reason_drop net/core/skbuff.c:1189 [inline] WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 sk_skb_reason_drop+0x76/0x170 net/core/skbuff.c:1214 struct tc_skb_cb has been added in commit ec624fe740b4 ("net/sched: Extend qdisc control block with tc control block"), which added a wrong interaction with db58ba459202 ("bpf: wire in data and data_end for cls_act_bpf"). drop_reason was added later. Add bpf_prog_run_data_pointers() helper to save/restore the net_sched storage colliding with BPF data_meta/data_end.

Affected products

Linux kernel: from 5.15.13 before 5.15.197; 5.16 — fixed in 5.15.197, 6.18

How to fix

Upgrade to a fixed version: Linux kernel 5.15.197, 6.18. Check the vendor advisory for mitigations.

References

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