In the Linux kernel, the following vulnerability has been resolved:

net: enetc: fix the deadlock of enetc_mdio_lock

After applying the workaround for err050089, the LS1028A platform
experiences RCU stalls on RT kernel. This issue is caused by the
recursive acquisition of the read lock enetc_mdio_lock. Here list some
of the call stacks identified under the enetc_poll path that may lead to
a deadlock:

enetc_poll
-> enetc_lock_mdio
-> enetc_clean_rx_ring OR napi_complete_done
-> napi_gro_receive
-> enetc_start_xmit
-> enetc_lock_mdio
-> enetc_map_tx_buffs
-> enetc_unlock_mdio
-> enetc_unlock_mdio

After enetc_poll acquires the read lock, a higher-priority writer attempts
to acquire the lock, causing preemption. The writer detects that a
read lock is already held and is scheduled out. However, readers under
enetc_poll cannot acquire the read lock again because a writer is already
waiting, leading to a thread hang.

Currently, the deadlock is avoided by adjusting enetc_lock_mdio to prevent
recursive lock acquisition.

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8029-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8030-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8029-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8048-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8029-3 Linux kernel (Azure) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 17 Dec 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Tue, 16 Dec 2025 13:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: enetc: fix the deadlock of enetc_mdio_lock After applying the workaround for err050089, the LS1028A platform experiences RCU stalls on RT kernel. This issue is caused by the recursive acquisition of the read lock enetc_mdio_lock. Here list some of the call stacks identified under the enetc_poll path that may lead to a deadlock: enetc_poll -> enetc_lock_mdio -> enetc_clean_rx_ring OR napi_complete_done -> napi_gro_receive -> enetc_start_xmit -> enetc_lock_mdio -> enetc_map_tx_buffs -> enetc_unlock_mdio -> enetc_unlock_mdio After enetc_poll acquires the read lock, a higher-priority writer attempts to acquire the lock, causing preemption. The writer detects that a read lock is already held and is scheduled out. However, readers under enetc_poll cannot acquire the read lock again because a writer is already waiting, leading to a thread hang. Currently, the deadlock is avoided by adjusting enetc_lock_mdio to prevent recursive lock acquisition.
Title net: enetc: fix the deadlock of enetc_mdio_lock
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-16T13:30:21.539Z

Reserved: 2025-04-16T07:20:57.187Z

Link: CVE-2025-40347

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-16T14:15:46.470

Modified: 2025-12-18T15:08:25.907

Link: CVE-2025-40347

cve-icon Redhat

Severity : Important

Publid Date: 2025-12-16T00:00:00Z

Links: CVE-2025-40347 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.