CVE-2022-48846: block: release rq qos structures for queue without disk

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-16 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: block: release rq qos structures for queue without disk blkcg_init_queue() may add rq qos structures to request queue, previously blk_cleanup_queue() calls rq_qos_exit() to release them, but commit 8e141f9eb803 ("block: drain file system I/O on del_gendisk") moves rq_qos_exit() into del_gendisk(), so memory leak is caused because queues may not have disk, such as un-present scsi luns, nvme admin queue, ... Fixes the issue by adding rq_qos_exit() to blk_cleanup_queue() back. BTW, v5.18 won't need this patch any more since we move blkcg_init_queue()/blkcg_exit_queue() into disk allocation/release handler, and patches have been in for-5.18/block.

Affected products

Linux kernel: from 5.15 before 5.15.31; from 5.16 before 5.16.17 — fixed in 5.15.31, 5.16.17

How to fix

Upgrade to a fixed version: Linux kernel 5.15.31, 5.16.17. Check the vendor advisory for mitigations.

References

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