UBUNTU-CVE-2026-80610: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: net: enetc: fix potential divide-by-zero when numvsi is zero For i.MX94 series, all the standalone ENETCs do not support SR-IOV, so pf->caps.numvsi is zero. This leads to a divide-by-zero in enetc4defaultringsallocation() when distributing rings among PF and VFs. Division by zero is undefined behavior in C. On ARM64, the UDIV/SDIV instructions silently return zero rather than raising an exception, so the issue does not cause a visible crash. However, relying on this behavior is incorrect and poses a cross-platform compatibility risk. Add an explicit check for numvsi == 0 and return early after the PF's rings have been configured.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
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ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Compensating control
In enetc4_default_rings_allocation(), explicitly check whether num_vsi == 0 and return early after the PF's rings have been configured, preventing division by zero when distributing rings among the PF and VFs.
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
The issue applies to affected Ubuntu kernel packages when using standalone ENETC hardware on the i.MX94 series, where SR-IOV is unsupported and the ENETC capability value num_vsi is zero.
Does this necessarily cause a visible crash?
No. On ARM64, the UDIV and SDIV instructions return zero for this condition rather than raising an exception, so the problem may not produce a visible crash. The behavior remains undefined in C and can create cross-platform compatibility risk.
What configuration triggers the divide-by-zero?
It is triggered when enetc4_default_rings_allocation() distributes rings between the physical function and virtual functions while pf->caps.num_vsi is zero. This occurs on the specified standalone i.MX94 ENETC devices because they do not support SR-IOV.
What does the fix change?
The fix explicitly checks whether num_vsi is zero and returns after configuring the physical function's rings, avoiding ring distribution logic that would divide by zero.