CVE-2024-26627

scsi: core: Move scsi_host_busy() out of host lock for waking up EH handler

Published Mar 6, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
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]

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-3842-1 linux-5.10 security update
Debian DSA Debian DSA DSA-5658-1 linux security update
Debian DSA Debian DSA DSA-5681-1 linux security update
EUVD EUVD EUVD-2024-23889 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]
Ubuntu USN Ubuntu USN USN-6688-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6766-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6766-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6766-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6795-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-2 Linux kernel (ARM laptop) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-3 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-4 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-3 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-4 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-6828-1 Linux kernel (Intel IoTG) vulnerabilities
History
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 8:01 PM
Reserved
Feb 19, 2024, 2:20 PM
Status
Analyzed
Published
Mar 6, 2024, 7:15 AM
Modified
Jun 17, 2026, 7:17 AM
Severity
Low
Public date
Mar 6, 2024, 12:00 AM