CVE-2022-50554: blk-mq: avoid double ->queue_rq() because of early timeout

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: 2025-10-07 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: blk-mq: avoid double ->queue_rq() because of early timeout David Jeffery found one double ->queue_rq() issue, so far it can be triggered in VM use case because of long vmexit latency or preempt latency of vCPU pthread or long page fault in vCPU pthread, then block IO req could be timed out before queuing the request to hardware but after calling blk_mq_start_request() during ->queue_rq(), then timeout handler may handle it by requeue, then double ->queue_rq() is caused, and kernel panic. So far, it is driver's responsibility to cover the race between timeout and completion, so it seems supposed to be solved in driver in theory, given driver has enough knowledge. But it is really one common problem, lots of driver could have similar issue, and could be hard to fix all affected drivers, even it isn't easy for driver to handle the race. So David suggests this patch by draining in-progress ->queue_rq() for solving this issue.

Affected products

Linux kernel: from 4.18 before 6.0.16; from 6.1 before 6.1.2 — fixed in 6.0.16, 6.1.2

How to fix

Upgrade to a fixed version: Linux kernel 6.0.16, 6.1.2. Check the vendor advisory for mitigations.

References

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