Improper Resource Locking Affecting kernel-kdump package, versions *


Severity

Recommended
low

Based on CentOS security rating.

Threat Intelligence

EPSS
0.04% (12th percentile)

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  • Snyk IDSNYK-CENTOS6-KERNELKDUMP-6411418
  • published7 Mar 2024
  • disclosed6 Mar 2024

Introduced: 6 Mar 2024

CVE-2024-26627  (opens in a new tab)
CWE-413  (opens in a new tab)

How to fix?

There is no fixed version for Centos:6 kernel-kdump.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-kdump package and not the kernel-kdump package as distributed by Centos. See How to fix? for Centos:6 relevant fixed versions and status.

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]

CVSS Scores

version 3.1