cve/2024/CVE-2024-36908.md

### [CVE-2024-36908](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-36908)
![](https://img.shields.io/static/v1?label=Product&message=Linux&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=7caa47151ab2e644dd221f741ec7578d9532c9a3%3C%2056a9d07f427378eeb75b917bb49c6fbea8204126%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

In the Linux kernel, the following vulnerability has been resolved:blk-iocost: do not WARN if iocg was already offlinedIn iocg_pay_debt(), warn is triggered if 'active_list' is empty, whichis intended to confirm iocg is active when it has debt. However, warncan be triggered during a blkcg or disk removal, if iocg_waitq_timer_fn()is run at that time:  WARNING: CPU: 0 PID: 2344971 at block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190  Call trace:  iocg_pay_debt+0x14c/0x190  iocg_kick_waitq+0x438/0x4c0  iocg_waitq_timer_fn+0xd8/0x130  __run_hrtimer+0x144/0x45c  __hrtimer_run_queues+0x16c/0x244  hrtimer_interrupt+0x2cc/0x7b0The warn in this situation is meaningless. Since this iocg is beingremoved, the state of the 'active_list' is irrelevant, and 'waitq_timer'is canceled after removing 'active_list' in ioc_pd_free(), which ensuresiocg is freed after iocg_waitq_timer_fn() returns.Therefore, add the check if iocg was already offlined to avoid warnwhen removing a blkcg or disk.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/bygregonline/devsec-fastapi-report