Bug 2525384 (CVE-2026-80610)

Summary: CVE-2026-80610 kernel: net: enetc: fix potential divide-by-zero when num_vsi is zero
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `net: enetc` module. When the `num_vsi` value is zero, a divide-by-zero error occurs during the allocation of network rings. While this issue may not cause an immediate system crash on some architectures, it represents undefined behavior that could lead to system instability or unexpected operational issues, particularly across different computing platforms.
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Description OSIDB Bzimport 2026-08-28 07:42:14 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: enetc: fix potential divide-by-zero when num_vsi is zero

For i.MX94 series, all the standalone ENETCs do not support SR-IOV, so
pf->caps.num_vsi is zero. This leads to a divide-by-zero in
enetc4_default_rings_allocation() 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 num_vsi == 0 and return early after the PF's
rings have been configured.
Comment 1 gkamathe 2026-08-31 08:10:24 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082834-CVE-2026-80610-9039@gregkh/T