CVE-2025-21925: Linux kernel · llc: do not use skb_get() before dev_queue_xmit()
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 10 Nov 2026, 14:48 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 1 Apr 2025
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 10 Nov 2026.
What to do
AI-suggested
A fix is available that replaces skb_get() with skb_clone() in the affected Linux kernel source file net/llc/llc_s_ac.c. Users should update to a Linux kernel version that includes this fix. Since this is a kernel-level issue, applying the official kernel patch or upgrading to a fixed kernel release is the recommended remediation.
Description
A vulnerability in the Linux kernel's LLC (Logical Link Control) networking code was fixed by replacing skb_get() with skb_clone() before calling dev_queue_xmit(). The issue could cause kernel crashes when using LLC with devices that do not support IFF_TX_SKB_SHARING, notably affecting the e1000 driver. This flaw was identified through syzbot testing and results in kernel BUGs and invalid opcode exceptions.
References
- git.kernel.org/stable/c/cd1c44327bbbd50fc24f2b38892f5f328b784d0f (opens in a new tab)
- git.kernel.org/stable/c/13f3f872627f0f27c31245524fc11367756240ad (opens in a new tab)
- git.kernel.org/stable/c/9b6f083db141ece0024be01526aa05aa978811cb (opens in a new tab)
- git.kernel.org/stable/c/17f86e25431ebc15aa9245ff156414fdad47822d (opens in a new tab)
- git.kernel.org/stable/c/416e8b4c20c6398044e93008deefd563289f477d (opens in a new tab)
- git.kernel.org/stable/c/0f764208dc24ea043c3e20194d32aebf94f8459c (opens in a new tab)
- git.kernel.org/stable/c/056e8a46d79e22983bae4267e0d9c52927076f46 (opens in a new tab)
- git.kernel.org/stable/c/64e6a754d33d31aa844b3ee66fb93ac84ca1565e (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)