CVE-2024-36971: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-36971 is a Use-After-Free (UAF) vulnerability discovered in the Linux kernel's network route management functionality. The vulnerability specifically affects the _dstnegativeadvice() function, which fails to enforce proper RCU (Read-Copy-Update) rules when sk->dstcache needs to be cleared. The issue was discovered by Clement Lecigne and affects Linux kernel versions from 4.6 up to versions before 6.9.4 (NVD).

The vulnerability stems from incorrect ordering of operations in the dstnegativeadvice() function. The proper RCU protocol requires first clearing sk->skdstcache, then calling dstrelease(olddst). While skdstreset(sk) implements this protocol correctly, dstnegativeadvice() executes these operations in the wrong order. The issue became particularly visible with UDP sockets after a specific commit (Kernel Patch). 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 can lead to a Use-After-Free condition in the network route management system, potentially allowing an attacker to execute code, cause system crashes, or escalate privileges. The high CVSS score indicates potential for significant impact on system confidentiality, integrity, and availability (NVD).

The vulnerability has been patched in multiple Linux kernel versions. Red Hat has released security updates for affected versions, including kernel version 4.18.0-477.67.1.el8_8 and others. System administrators are advised to apply the available kernel updates according to their distribution's guidance (Red Hat).