CVE-2022-50086 block: don't allow the same type rq_qos add more than once

What is CVE-2022-50086?

CVE-2022-50086 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

block: don't allow the same type rq_qos add more than once

In our test of iocost, we encountered some list add/del corruptions of inner_walk list in ioc_timer_fn.

The reason can be described as follows:

cpu 0 cpu 1 ioc_qos_write ioc_qos_write

ioc = q_to_ioc(queue); if (!ioc) { ioc = kzalloc(); ioc = q_to_ioc(queue); if (!ioc) { ioc = kzalloc(); ... rq_qos_add(q, rqos); } ... rq_qos_add(q, rqos); ... }

When the io.cost.qos file is written by two cpus concurrently, rq_qos may be added to one disk twice. In that case, there will be two iocs enabled and running on one disk. They own different iocgs on their active list. In the ioc_timer_fn function, because of the iocgs from two iocs have the same root iocg, the root iocg's walk_list may be overwritten by each other and this leads to list add/del corruptions in building or destroying the inner_walk list.

And so far, the blk-rq-qos framework works in case that one instance for one type rq_qos per queue by default. This patch make this explicit and also fix the crash above.

Which versions are affected by CVE-2022-50086?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-50086?

Apply the vendor's patch.

Is CVE-2022-50086 being exploited?

There is no known exploitation of CVE-2022-50086 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2022-50086, GHSA-jcww-gc65-wfhf, ROOT-OS-DEBIAN-11-CVE-2022-50086, UBUNTU-CVE-2022-50086.