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Fencer Vulns
high 7.5

CVE-2024-26690 json

net: stmmac: protect updates of 64-bit statistics counters

published 2024-04-03 2 y ago modified 2026-10-30 10 d ago also EUVD-2024-23952

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

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

net: stmmac: protect updates of 64-bit statistics counters

As explained by a comment in <linux/u64_stats_sync.h>, write side of struct u64_stats_sync must ensure mutual exclusion, or one seqcount update could be lost on 32-bit platforms, thus blocking readers forever. Such lockups have been observed in real world after stmmac_xmit() on one CPU raced with stmmac_napi_poll_tx() on another CPU.

To fix the issue without introducing a new lock, split the statics into three parts:

1. fields updated only under the tx queue lock, 2. fields updated only during NAPI poll, 3. fields updated only from interrupt context,

Updates to fields in the first two groups are already serialized through other locks. It is sufficient to split the existing struct u64_stats_sync so that each group has its own.

Note that tx_set_ic_bit is updated from both contexts. Split this counter so that each context gets its own, and calculate their sum to get the total value in stmmac_get_ethtool_stats().

For the third group, multiple interrupts may be processed by different CPUs at the same time, but interrupts on the same CPU will not nest. Move fields from this group to a newly created per-cpu struct stmmac_pcpu_stats.

Patch / fix

  • Linux Linux 6.1.191, 6.6.18, 6.7.6, 6.8
  • linux Debian 14, Debian 13 6.7.7-1

debian advisories DEBIAN-CVE-2024-26690

  • linux-raspi-realtime Ubuntu Pro Realtime 24.04 LTS 6.8.0-2001.1

ubuntu advisories UBUNTU-CVE-2024-26690

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

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-2024-26690 updated cvss 4.4

kernel: net: stmmac: protect updates of 64-bit statistics counters

  • 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
    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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.86% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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