CVE-2026-74736: net/sched: cls_bpf: reject dev-bound programs bound to a different device

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-26 · updated 2026-10-16

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_bpf: reject dev-bound programs bound to a different device cls_bpf_prog_from_efd() obtained a SCHED_CLS program via bpf_prog_get_type_dev() but never verified that a device-bound (offloaded) program's bound netdev matches the TC netdev the classifier is being attached to. This let a program loaded with prog_ifindex for device A be attached via cls_bpf + skip_sw to device B; deleting device A then destroyed the program's offload state while it was still attached to device B, triggering a netdevsim WARN (panic with panic_on_warn=1). Mirror the XDP attach path (net/core/dev.c) and reject the attach with -EINVAL when a dev-bound program's bound device does not match the target device.

Affected products

Linux kernel: 6.3 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

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