CVE-2024-36908

blk-iocost: do not WARN if iocg was already offlined

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved:

blk-iocost: do not WARN if iocg was already offlined

In iocg_pay_debt(), warn is triggered if 'active_list' is empty, which
is intended to confirm iocg is active when it has debt. However, warn
can 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/0x7b0

The warn in this situation is meaningless. Since this iocg is being
removed, the state of the 'active_list' is irrelevant, and 'waitq_timer'
is canceled after removing 'active_list' in ioc_pd_free(), which ensures
iocg is freed after iocg_waitq_timer_fn() returns.

Therefore, add the check if iocg was already offlined to avoid warn
when removing a blkcg or disk.

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: blk-iocost: no ADVERTIR si iocg ya estaba desconectado. En iocg_pay_debt(), se activa una advertencia si 'active_list' está vacía, lo que pretende confirmar que iocg está activo cuando deuda. Sin embargo, se puede activar una advertencia durante un blkcg o la eliminación de un disco, si se ejecuta iocg_waitq_timer_fn() en ese momento: ADVERTENCIA: CPU: 0 PID: 2344971 en block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190 Seguimiento de llamadas: 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/0x7b0 La advertencia en esta situación es sin sentido. Dado que este iocg se está eliminando, el estado de 'active_list' es irrelevante y 'waitq_timer' se cancela después de eliminar 'active_list' en ioc_pd_free(), lo que garantiza que iocg se libere después de que iocg_waitq_timer_fn() regrese. Por lo tanto, agregue la verificación si iocg ya estaba desconectado para evitar advertencias al eliminar un blkcg o un disco.

*Credits: N/A

CVSS Scores

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-30 CVE Reserved
2024-05-30 CVE Published
2024-05-31 EPSS Updated
2024-08-02 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (3)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/1c172ac7afe4442964f4153b2c78fe4e005d9d67	2024-05-17
https://git.kernel.org/stable/c/14b3275f93d4a0d8ddc02195bc4e9869b7a3700e	2024-05-17
https://git.kernel.org/stable/c/01bc4fda9ea0a6b52f12326486f07a4910666cf6	2024-04-19

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 6.6.31 Search vendor "Linux" for product "Linux Kernel" and version " < 6.6.31"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 6.8.10 Search vendor "Linux" for product "Linux Kernel" and version " < 6.8.10"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 6.9 Search vendor "Linux" for product "Linux Kernel" and version " < 6.9"		en		Affected