CVE-2026-43042: mpls: add seqcount to protect the platform_label{,s} pair
In the Linux kernel, the following vulnerability has been resolved:
mpls: add seqcount to protect the platformlabel{,s} pair
The RCU-protected codepaths (mplsforward, mplsdumproutes) can have an inconsistent view of platformlabels vs platformlabel in case of a concurrent resize (resizeplatformlabeltable, under platformmutex). This can lead to OOB accesses.
This patch adds a seqcount, so that we get a consistent snapshot.
Note that mplslabelok is also susceptible to this, so the check against RTADST in rtmtorouteconfig, done outside platformmutex, is not sufficient. This value gets passed to mplslabelok once more in both mplsrouteadd and mplsroutedel, so there is no issue, but that additional check must not be removed.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1035.38 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 7.0.0-1006.6 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.19.12-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 7.2.12-1Fixed in 7.2.14-1 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.191 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.160 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.114 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.19.12
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43042?
CVE-2026-43042 has a high severity rating due to its potential impact on the integrity of platform_labels in the Linux kernel.
How do I fix CVE-2026-43042?
To fix CVE-2026-43042, update your Linux kernel to the latest version that includes the security patch addressing this vulnerability.
Which versions of the Linux kernel are affected by CVE-2026-43042?
CVE-2026-43042 affects multiple versions of the Linux kernel prior to the application of the security patch.
What are the potential effects of exploiting CVE-2026-43042?
Exploiting CVE-2026-43042 can lead to inconsistent views of platform_labels, which may cause security and stability issues in the Linux environment.
Is CVE-2026-43042 related to any specific Linux distributions?
CVE-2026-43042 is relevant to all Linux distributions using the affected kernel versions.