Bug 2541153 (CVE-2026-97963)

Summary: CVE-2026-97963 kernel: net: stmmac: initialize ptp_lock at probe time
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
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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Doc Text:
A flaw was found in the Linux kernel's stmmac network driver. An uninitialized read-write lock is accessed when configuring traffic control scheduling on an interface that has not been brought up. A local user with network administration privileges could exploit this flaw to cause a kernel crash, resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-25 10:52:48 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: stmmac: initialize ptp_lock at probe time

priv->ptp_lock is only initialized in stmmac_ptp_register(), which runs
during __stmmac_open(). However, the lock is also used while the
interface is down and has never been opened: tc_taprio_configure()
invokes the PTP gettime64() callback to compute the EST base time when
offloading a TAPRIO schedule, and stmmac_get_time() takes
priv->ptp_lock. Using an uninitialized rwlock is undefined behaviour.
Move the rwlock_init() to __stmmac_dvr_probe(), together with the other
private locks, so that ptp_lock is always valid regardless of the
interface state.
Comment 1 gkamathe 2026-09-30 03:57:04 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97963.mbox