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Vulnerability DatabaseCVE-2025-21868
CVE-2025-21868:
Linux Kernel vulnerability analysis and mitigation
Overview
CVE-2025-21868 was disclosed on March 27, 2025, affecting the Linux kernel. The vulnerability relates to a buffer cache usage issue with large MAX_SKB_FRAGS values, specifically in the network subsystem (NVD).
Technical details
The vulnerability manifests when the kernel is built with MAX_SKB_FRAGS=45, where SKB_WITH_OVERHEAD(1024) is smaller than GRO_MAX_HEAD. This condition affects the napi_get_frags() function, which uses the page frag allocator and triggers a warning in the netif_napi_add_weight_locked function (NVD).
Impact
The vulnerability affects the network subsystem's buffer management functionality, potentially leading to system instability or crashes when processing network packets under specific conditions (NVD).
Exploitability
The vulnerability requires specific kernel configuration settings and conditions to be exploitable. No active exploits have been reported in the wild (NVD).
Mitigation and workarounds
The issue has been resolved in the Linux kernel through updates to ensure that small head cache will fit both TCP and GRO allocation, with modifications to napi_alloc_skb() and __netdev_alloc_skb() functions to properly handle kmalloc() usage (NVD).
Additional resources
Source: This report was generated using AI
Related Linux Kernel vulnerabilities:
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