Bug 2492844 (CVE-2026-53231)

Summary: CVE-2026-53231 kernel: net: phy: don't try to setup PHY-driven SFP cages when using genphy
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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OS: Linux   
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Description OSIDB Bzimport 2026-06-25 10:08:41 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: phy: don't try to setup PHY-driven SFP cages when using genphy

We don't have support for PHY-driver SFP cages with the genphy code.

On top of that, it was found by sashiko that running
sfp_bus_add_upstream() for genphy deadlocks, as for genphy the PHY
probing runs under RTNL, which isn't the case for non-genphy drivers.

This problem was reproduced, and does lead to a deadlock on RTNL.

Before the blamed commit, the phy_sfp_probe() call was made by
individual PHY drivers, so there was no way to get to the SFP probing
path when using genphy.

Let's therefore only run phy_sfp_probe when not using genphy.
Comment 1 Mauro Matteo Cascella 2026-06-29 14:58:42 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062508-CVE-2026-53231-90cc@gregkh/T