CVE-2026-90183

/// Technical description

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

blk-iolatency: clear delay state when freeing policy data

io.latency can throttle a group which has no latency target of its own.

When a sibling misses its target, check_scale_change() scales down its

peers, and a peer that reaches queue depth one gets blkcg_use_delay()

called on it on every further scale-down, even with min_lat_nsec == 0.

iolatency_pd_offline() resets the target through

iolatency_set_min_lat_nsec(), which clears the delay only on a nonzero

to zero transition, so it never clears such a peer. Freeing the policy

data then leaves blkg->use_delay set and blkcg->congestion_count

elevated with nothing left that can drop it.

blk_cgroup_congested() then returns true for every task in that cgroup

and its descendants for as long as the cgroup lives: page_cache_sync_ra()

cuts readahead to a single page, page_cache_async_ra() skips it

altogether, and __folio_throttle_swaprate() takes swap_avail_lock and

sched

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References