CVE-2026-100071

net: hsr: free learned nodes on device setup failure

Published Sep 25, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

net: hsr: free learned nodes on device setup failure

hsr_dev_finalize() can fail after a lower-device RX handler has
already been registered (slave A is added before the failable slave B
and interlink adds). RX handlers run in softirq regardless of the
master's state, so frames received in that window can learn dynamic
nodes into node_db, and the error unwind never releases them.

Free both owned dynamic databases in the unwind, mirroring
hsr_dellink(). proxy_node_db is provably empty on every current error
exit (only interlink RX feeds it, and the interlink add is the last
failable step) and is freed for symmetry. The order is safe:
hsr_del_port() unregisters each RX handler with synchronize_net()
before hsr_del_nodes() runs, which removes remaining entries with
list_del_rcu() and defers their release with call_rcu() for readers
already under RCU.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4841-1 linux security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9022-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9023-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9024-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9025-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9026-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9039-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-9040-1 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9066-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities
History
Type Values Removed Values Added
Weaknesses NVD-CWE-noinfo
Type Values Removed Values Added
Weaknesses CWE-401
Type Values Removed Values Added
Weaknesses CWE-772
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low

Type Values Removed Values Added
Weaknesses CWE-401
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: hsr: free learned nodes on device setup failure hsr_dev_finalize() can fail after a lower-device RX handler has already been registered (slave A is added before the failable slave B and interlink adds). RX handlers run in softirq regardless of the master's state, so frames received in that window can learn dynamic nodes into node_db, and the error unwind never releases them. Free both owned dynamic databases in the unwind, mirroring hsr_dellink(). proxy_node_db is provably empty on every current error exit (only interlink RX feeds it, and the interlink add is the last failable step) and is freed for symmetry. The order is safe: hsr_del_port() unregisters each RX handler with synchronize_net() before hsr_del_nodes() runs, which removes remaining entries with list_del_rcu() and defers their release with call_rcu() for readers already under RCU.
Title net: hsr: free learned nodes on device setup failure
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 19, 2026, 8:43 AM
Reserved
Sep 25, 2026, 10:25 AM
Status
Analyzed
Published
Sep 25, 2026, 2:17 PM
Modified
Oct 21, 2026, 6:46 PM
Severity
Low
Public date
Sep 25, 2026, 12:00 AM