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Fencer Vulns
no cvss —

CVE-2026-90083 json

net/sched: act_ife: Only operate on Ethernet frames

published 2026-09-17 52 d ago modified 2026-10-30 9 d ago also EUVD-2026-81944

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

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

net/sched: act_ife: Only operate on Ethernet frames

act_ife encapsulates/decapsulates the original Ethernet header and uses skb->dev->hard_header_len as the length of that header. That is only correct for Ethernet devices: on a device where hard_header_len does not match the L2 header that was actually pulled (PPP reports PPP_HDRLEN while nothing is stripped on ingress), the ingress skb_push()/skb_pull() use the wrong length and can hit skb_under_panic when headroom is tight.

IFE is Ethernet-only by design - it builds an outer ethhdr, rewrites h_source/h_dest/h_proto, and calls eth_type_trans() on decode - so instead of trying to make the offsets work for arbitrary link types, simply drop packets that do not carry an Ethernet header.

Checking skb->dev->type alone is not enough. We have to cater for a corner case where mirred can redirect an skb from a non-Ethernet device to an Ethernet one, and skb->dev then says nothing about the framing the skb actually has: an skb redirected from ppp0 reaches the target's ingress hook with mac_len 0 and no Ethernet header at all. So at ingress also require mac_len to be ETH_HLEN. On egress mac_len is not maintained, so the device type is all we have; a bogus redirect there yields a malformed frame rather than an out-of-bounds push, and it would be malformed with or without IFE.

That corner case is not theoretical - redirecting from ppp0 into a veth that has an ife encode action on its ingress hook panics without this patch:

skbuff: skb_under_panic: len:98 put:14 head:ffff88800e410000 data:ffff88800e40fff5 tail:0x57 end:0x640 dev:veth3 kernel BUG at net/core/skbuff.c:214! Call Trace: skb_push (net/core/skbuff.c:224 net/core/skbuff.c:2657) tcf_ife_act (net/sched/act_ife.c:829 net/sched/act_ife.c:874) tc_run (net/core/dev.c:4463) netif_receive_skb (net/core/dev.c:6463 net/core/dev.c:6522) tcf_mirred_to_dev (net/sched/act_mirred.c:248 net/sched/act_mirred.c:328) tcf_mirred_act (net/sched/act_mirred.c:489) tc_run (net/core/dev.c:4463) process_backlog (net/core/dev.c:6728)

With Ethernet framing guaranteed, use ETH_HLEN instead of hard_header_len.

Patch / fix

  • Linux Linux 6.1.191, 6.6.160, 6.12.114, 6.18.52, 7.2.6, 7.3
  • linux Debian 13 6.12.115-2
  • linux Debian 14 7.2.6-1

debian advisories DEBIAN-CVE-2026-90083

  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
  • linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
  • linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17

ubuntu advisories UBUNTU-CVE-2026-90083

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source openSUSE Tumbleweed 7.2.7-1.1

opensuse advisories openSUSE-SU-2026:11880-1

  • kernel Azure Linux 3.0 6.6.161.1-1

azure linux advisories AZL-102546

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-90083 updated cvss 5.5

kernel: net/sched: act_ife: Only operate on Ethernet frames

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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