In the Linux kernel, the following vulnerability has been resolved: scsi: core: Move scsi_host_busy() out of host lock for waking up EH handler Inside scsi_eh_wakeup(), scsi_host_busy() is called & checked with host lock every time for deciding if error handler kthread needs to be waken up. This can be too heavy in case of recovery, such as: - N hardware queues - queue depth is M for each hardware queue - each scsi_host_busy() iterates over (N * M) tag/requests If recovery is triggered in case that all requests are in-flight, each scsi_eh_wakeup() is strictly serialized, when scsi_eh_wakeup() is called for the last in-flight request, scsi_host_busy() has been run for (N * M - 1) times, and request has been iterated for (N*M - 1) * (N * M) times. If both N and M are big enough, hard lockup can be triggered on acquiring host lock, and it is observed on mpi3mr(128 hw queues, queue depth 8169). Fix the issue by calling scsi_host_busy() outside the host lock. We don't need the host lock for getting busy count because host the lock never covers that. [mkp: Drop unnecessary 'busy' variables pointed out by Bart]
History

Tue, 05 Nov 2024 10:45:00 +0000

Type Values Removed Values Added
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-03-06T06:45:34.339Z

Updated: 2024-11-05T09:12:50.090Z

Reserved: 2024-02-19T14:20:24.135Z

Link: CVE-2024-26627

cve-icon Vulnrichment

Updated: 2024-08-02T00:07:19.707Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-03-06T07:15:12.973

Modified: 2024-11-05T10:15:34.750

Link: CVE-2024-26627

cve-icon Redhat

Severity : Low

Publid Date: 2024-03-06T00:00:00Z

Links: CVE-2024-26627 - Bugzilla