CVE-2026-23110 scsi: core: Wake up the error handler when final completions race against each other

What is CVE-2026-23110?

CVE-2026-23110 is a medium-severity vulnerability in Linux kernel, published on 4 Feb 2026. 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:

scsi: core: Wake up the error handler when final completions race against each other

The fragile ordering between marking commands completed or failed so that the error handler only wakes when the last running command completes or times out has race conditions. These race conditions can cause the SCSI layer to fail to wake the error handler, leaving I/O through the SCSI host stuck as the error state cannot advance.

First, there is an memory ordering issue within scsi_dec_host_busy(). The write which clears SCMD_STATE_INFLIGHT may be reordered with reads counting in scsi_host_busy(). While the local CPU will see its own write, reordering can allow other CPUs in scsi_dec_host_busy() or scsi_eh_inc_host_failed() to see a raised busy count, causing no CPU to see a host busy equal to the host_failed count.

This race condition can be prevented with a memory barrier on the error path to force the write to be visible before counting host busy commands.

Second, there is a general ordering issue with scsi_eh_inc_host_failed(). By counting busy commands before incrementing host_failed, it can race with a final command in scsi_dec_host_busy(), such that scsi_dec_host_busy() does not see host_failed incremented but scsi_eh_inc_host_failed() counts busy commands before SCMD_STATE_INFLIGHT is cleared by scsi_dec_host_busy(), resulting in neither waking the error handler task.

This needs the call to scsi_host_busy() to be moved after host_failed is incremented to close the race condition.

Weakness: CWE-362

Which versions are affected by CVE-2026-23110?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23110?

Apply the vendor's patch.

Is CVE-2026-23110 being exploited?

There is no known exploitation of CVE-2026-23110 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 AZL-77118, BELL-CVE-2026-23110, DEBIAN-CVE-2026-23110, GHSA-7p3h-gfr2-rwcv, ROOT-OS-UBUNTU-2204-CVE-2026-23110, ROOT-OS-UBUNTU-2404-CVE-2026-23110 and 1 more.