Bug 2555166 (CVE-2026-98795)

Summary: CVE-2026-98795 kernel: net: sparx5: skip ptp deinit if init was skipped
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Microchip Sparx5 network driver. When operating on devices where Precision Time Protocol (PTP) initialization is skipped, the driver does not check if PTP was initialized before executing its deinitialization routines. A local privileged user could trigger this vulnerability by unbinding the driver or removing the device, resulting in a NULL pointer dereference, kernel crash, and Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-18 15:58:09 UTC
In the Linux kernel, the following vulnerability has been resolved:

net: sparx5: skip ptp deinit if init was skipped

sparx5_ptp_init() returns early on the base lan969x variants
because they do not have the SPX5_FEATURE_PTP flag. It also returns early
when no "ptp" interrupt is described. Unbinding the driver then causes a
NULL pointer dereference when cleaning up uninitialized tx_skbs queues:

    Unable to handle kernel NULL pointer dereference at virtual address
    0000000000000008
    Call trace:
    skb_queue_purge_reason+0x68/0x120 (P)
    sparx5_ptp_deinit+0x64/0xc0
    mchp_sparx5_remove+0x38/0x70
    platform_remove+0x20/0x30
    device_remove+0x4c/0x80

Before per-port tx_skbs were added, a NULL dereference would have happened
when calling ptp_clock_unregister() on the never-registered PTP clocks.

Fix by returning early in sparx5_ptp_deinit() if PTP is not used.