Fixed
Created: May 30, 2024
Updated: Dec 7, 2025
Resolved Date: Nov 27, 2025
Found In Version: 10.21.20.1
Fix Version: 10.21.20.26
Severity: Standard
Applicable for: Wind River Linux LTS 21
Component/s: Kernel
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.
