Cloud Vulnerability DB
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Vulnerability DatabaseCVE-2025-21925
CVE-2025-21925:
Linux Kernel vulnerability analysis and mitigation
Overview
CVE-2025-21925 is a vulnerability discovered in the Linux kernel affecting the LLC (Logical Link Control) networking component. The vulnerability was disclosed on April 1, 2025, and involves improper handling of socket buffer (skb) sharing in the LLC implementation (NVD).
Technical details
The vulnerability stems from incorrect usage of skb_get() before dev_queue_xmit() in the LLC networking stack. The issue specifically affects devices not supporting IFF_TX_SKB_SHARING, where the e1000 driver calls eth_skb_pad() while the skb is shared. The technical solution involves replacing skb_get() with skb_clone() in net/llc/llc_s_ac.c (NVD).
Impact
When exploited, this vulnerability can lead to kernel crashes, as demonstrated by syzbot testing. The issue manifests as a kernel BUG at net/core/skbuff.c:2178, resulting in system instability (NVD).
Exploitability
The vulnerability has been demonstrated to be exploitable through syzbot testing, which successfully triggered kernel crashes. The exploit specifically targets the interaction between LLC networking code and network devices that don't support IFF_TX_SKB_SHARING (NVD).
Mitigation and workarounds
The vulnerability has been addressed in Linux kernel version 6.1.133-1 as part of a security update. The fix involves replacing skb_get() with skb_clone() in the LLC networking code (Debian Security).
Additional resources
Linux Distribution fix status
Fix availability across major Linux distributions and their releases.
bionic (esm-infra)
linux
bionic (fips-updates)
linux-fips
bionic (fips)
linux-fips
devel
linux
focal
linux: 5.4.0-216.236
focal (esm-infra)
linux: 5.4.0-216.236
focal (fips-updates)
linux-fips: 5.4.0-1120.130
focal (fips)
linux-fips
Source: This report was generated using AI
Related Linux Kernel vulnerabilities:
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