CVE-2024-35974: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-35974 affects the Linux kernel's block subsystem, specifically related to disk rebinding operations. The vulnerability was discovered and disclosed on May 20, 2024, and involves a corruption issue in the q->blkg_list during disk rebind operations. This vulnerability affects multiple Linux kernel versions and distributions, including Ubuntu 24.04 LTS and various other Linux distributions (Ubuntu Security, NVD).

The vulnerability occurs when multiple gendisk instances are allocated/added for a single request queue during disk rebind operations. The issue arises because blkg may remain in q->blkg_list when calling blkcg_init_disk() for rebind, resulting in q->blkg_list corruption. The vulnerability originated from commit f1c006f1c685 which delayed removing blkg from q->blkg_list into blkg_free_workfn() (Kernel Commit).

The corruption of q->blkg_list can potentially lead to system instability and reliability issues in the Linux kernel's block subsystem, particularly affecting disk operations and block device management (NVD).

The issue has been fixed by implementing two main changes: 1) Adding blkg_init_queue() to initialize q->blkg_list & q->blkcg_mutex only, and 2) Moving the blkg_init_queue() call into blk_alloc_queue(). The fix has been implemented in various Linux distributions, including Ubuntu 24.04 LTS (noble) with version 6.8.0-38.38 (Ubuntu Security).