CVE-2026-68301: Linux kernel · net: hsr: fix memory leak on slave unregistration by removing synced VLANs
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in f72c312af6c7897ab0f8a2b5a63f917a207a4143 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 17:04 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in f72c312af6c7897ab0f8a2b5a63f917a207a4143, dcf15eaf5641812f1cfc5e96537380132a7da89d, ccc822e9e4f09a6c2ca73ad5334570441947f94f +8
Exploitation evidence
Disclosed: evidence found.
CVE published 10 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: net: hsr: fix memory leak on slave unregistration by removing synced VLANs When an HSR master device is brought UP, it auto-adds VLAN 0 via vlan_vid0_add(), which propagates VID 0 to its slave devices (slave A and B). If a slave device is later unregistered while HSR is active (e.g., during netns cleanup or interface destruction), hsr_del_port() is called to detach the slave port from the HSR master. However, hsr_del_port() currently does not delete the VLAN IDs that were synced to the slave device by HSR. As a result, the slave device retains a refcount on VID 0 (and any other synced VLANs). When the slave device is destroyed, its vlan_info / vlan_vid_info structure remains allocated, leading to a memory leak. Fix this by calling vlan_vids_del_by_dev(port->dev, master->dev) in hsr_del_port() before unlinking slave A or slave B ports, matching the propagation logic in hsr_ndo_vlan_rx_add_vid() / hsr_ndo_vlan_rx_kill_vid() and the cleanup behavior in bonding and team drivers.
References
- git.kernel.org/stable/c/ccc822e9e4f09a6c2ca73ad5334570441947f94f (opens in a new tab)
- git.kernel.org/stable/c/79ff0547676acdeceda445c3fce4071b0a887b70 (opens in a new tab)
- git.kernel.org/stable/c/f72c312af6c7897ab0f8a2b5a63f917a207a4143 (opens in a new tab)
- git.kernel.org/stable/c/21d48408479a17eb65568a765930adea37e4d804 (opens in a new tab)
- git.kernel.org/stable/c/b5ded444621b6180df9f3d4e07045fc1fc1e8cd9 (opens in a new tab)
- git.kernel.org/stable/c/ae995b8002d3af134560a706c0e111a89e26317c (opens in a new tab)
- git.kernel.org/stable/c/dcf15eaf5641812f1cfc5e96537380132a7da89d (opens in a new tab)