CVE-2024-26666: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-26666 is a vulnerability in the Linux kernel's mac80211 subsystem, specifically affecting the TDLS (Tunneled Direct Link Setup) fast-xmit functionality. The vulnerability was discovered and disclosed in early 2024, with the initial fix being committed on January 29, 2024. The issue affects Linux kernel versions that implement the mac80211 wireless networking subsystem (Kernel Git).

The vulnerability stems from improper RCU (Read-Copy-Update) protection in the TDLS fast-xmit functionality. Specifically, the code looks up a link under RCU protection but doesn't guarantee that the protection is maintained throughout the operation. The issue was introduced in commit 8cc07265b691 'wifi: mac80211: handle TDLS data frames with MLO'. According to CISA's ADP assessment, the vulnerability has been assigned a CVSS v3.1 base score of 7.8 (HIGH) with vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (NVD).

The vulnerability could potentially lead to memory corruption or system instability due to improper RCU usage in the kernel's wireless networking stack. This could affect systems using wireless networking capabilities, particularly those utilizing TDLS functionality (Kernel Git).

The vulnerability has been fixed in various Linux kernel versions. Ubuntu has released patches for affected versions, including version 6.5.0-44.44 for Ubuntu 23.10 and version 6.5.0-1023.24 for Ubuntu 22.04 LTS. The fix involves properly protecting the RCU-protected link access by adding appropriate rcureadlock() and rcureadunlock() calls around the critical section (Ubuntu Security).