CVE-2026-93815 - Vulnerability Details

- net: au1000: move free_irq out of the close-time spinlocked section

Description

In the Linux kernel, the following vulnerability has been resolved:

net: au1000: move free_irq out of the close-time spinlocked section

au1000_close() calls free_irq() while aup->lock is still held with
spin_lock_irqsave(). free_irq() can sleep because it takes the IRQ
descriptor request mutex, so it does not belong inside the close-time
spinlocked section.

This was found by our static analysis tool and then confirmed by manual
review of the in-tree au1000_close() .ndo_stop path. The reviewed path
keeps aup->lock held across the MAC reset, queue stop and
free_irq(dev->irq, dev).

A directed runtime validation kept that ndo_stop carrier and the same
free_irq(dev->irq, dev) operation under the driver lock. Lockdep reported
"BUG: sleeping function called from invalid context" and "Invalid wait
context" while free_irq() was taking desc->request_mutex, with
au1000_close() and free_irq() on the stack.

Drop aup->lock before freeing the IRQ. The protected close-time work still
stops the device and queue before IRQ teardown, but the sleepable IRQ core
path now runs outside the spinlocked section.

Published: 2026-09-24

Score: 5.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

This bug resides in the Linux kernel au1000 network driver. The driver’s close routine calls free_irq while still holding a spinlock, which causes the kernel to sleep in a non‑sleepable context. This mismatch triggers lockdep errors such as "BUG: sleeping function called from invalid context" and can lead to a kernel panic or other instability. The flaw fits the concurrency weakness described by CWE-821.

Affected Systems

All Linux kernel releases that contain the au1000 driver are potentially affected. No specific kernel version list is provided in the vendor data, so any build exposing this driver is at risk.

Risk and Exploitability

The CVSS score is 5.5, the EPSS score is <1%, and the vulnerability is not listed in the CISA KEV catalog. This moderate‑severity kernel‑level concurrency issue can cause a crash or denial of service. An attacker must have sufficient privileges to trigger the close sequence (for example, by bringing down the device). Although exploitation evidence is lacking, the potential impact is serious due to kernel instability.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< f86bca5b7857b85bfa8afdb4fa895d7c0a3f7ebc
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< 26fd652915123a690f19d62b253b545a53f3cd51
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< d514b08ed61fdffe23604fd3e9e53c07cbe5ac3e
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< e1b5a13249975fec3cf654efa84f57118db2da2c
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< 4536667fba8ddbaff2f2a135080ae6aabf737b5e
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< fc2233f1ab2a1ca562869bca6987d7477671388c
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< f48763beab4eea41fc480c9702ec6eebe8d75e4f

Linux

affected

Version	Status	Constraints
`2.6.12`	affected	—
`0`	unaffected	< 2.6.12
`5.10.271`	unaffected	≤ 5.10.*
`5.15.222`	unaffected	≤ 5.15.*
`6.1.189`	unaffected	≤ 6.1.*
`6.6.158`	unaffected	≤ 6.6.*
`6.12.111`	unaffected	≤ 6.12.*
`6.18.53`	unaffected	≤ 6.18.*
`7.2`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,4536667fba8ddbaff2f2a135080ae6aabf737b5e)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,fc2233f1ab2a1ca562869bca6987d7477671388c)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,f48763beab4eea41fc480c9702ec6eebe8d75e4f)`	affected	code_commit	—
`[0,6.12.111)`	affected	semver	—
`[0,6.18.53)`	affected	semver	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[6.12.111,6.12.*]`	unaffected	generic	—
`[6.18.53,6.18.*]`	unaffected	generic	—
`[7.2,*]`	unaffected	generic	—

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Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Apply the kernel patch that moves free_irq out of the spinlocked section (commits 4536667fba8ddbaff2f2a135080ae6aabf737b5e or later).
If the patch cannot be applied, unload or disable the au1000 driver to prevent the close routine from executing.
Configure lockdep to warn on "sleeping function called from invalid context" and monitor kernel logs for related panics; apply fix promptly when detected.

Generated by OpenCVE AI on October 1, 2026 at 19:50 UTC.

Tracking

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Advisories

Source	ID	Title
Debian DLA	DLA-4817-1	linux-6.12 security update
Debian DLA	DLA-4841-1	linux security update
Debian DSA	DSA-6528-1	linux security update

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00173.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93815.mbox
https://git.kernel.org/stable/c/26fd652915123a690f19d62b253b545a53f3cd51
https://git.kernel.org/stable/c/4536667fba8ddbaff2f2a135080ae6aabf737b5e
https://git.kernel.org/stable/c/d514b08ed61fdffe23604fd3e9e53c07cbe5ac3e
https://git.kernel.org/stable/c/e1b5a13249975fec3cf654efa84f57118db2da2c
https://git.kernel.org/stable/c/f48763beab4eea41fc480c9702ec6eebe8d75e4f
https://git.kernel.org/stable/c/f86bca5b7857b85bfa8afdb4fa895d7c0a3f7ebc
https://git.kernel.org/stable/c/fc2233f1ab2a1ca562869bca6987d7477671388c
https://nvd.nist.gov/vuln/detail/CVE-2026-93815
https://www.cve.org/CVERecord?id=CVE-2026-93815

History

Sat, 03 Oct 2026 11:15:00 +0000

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/26fd652915123a690f19d62b253b545a53f3cd51 https://git.kernel.org/stable/c/d514b08ed61fdffe23604fd3e9e53c07cbe5ac3e https://git.kernel.org/stable/c/e1b5a13249975fec3cf654efa84f57118db2da2c https://git.kernel.org/stable/c/f86bca5b7857b85bfa8afdb4fa895d7c0a3f7ebc

Thu, 01 Oct 2026 17:00:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-727

Tue, 29 Sep 2026 13:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-821
References		https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93815.mbox https://nvd.nist.gov/vuln/detail/CVE-2026-93815 https://www.cve.org/CVERecord?id=CVE-2026-93815
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Moderate`

Fri, 25 Sep 2026 05:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-727

Thu, 24 Sep 2026 16:30:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: net: au1000: move free_irq out of the close-time spinlocked section au1000_close() calls free_irq() while aup->lock is still held with spin_lock_irqsave(). free_irq() can sleep because it takes the IRQ descriptor request mutex, so it does not belong inside the close-time spinlocked section. This was found by our static analysis tool and then confirmed by manual review of the in-tree au1000_close() .ndo_stop path. The reviewed path keeps aup->lock held across the MAC reset, queue stop and free_irq(dev->irq, dev). A directed runtime validation kept that ndo_stop carrier and the same free_irq(dev->irq, dev) operation under the driver lock. Lockdep reported "BUG: sleeping function called from invalid context" and "Invalid wait context" while free_irq() was taking desc->request_mutex, with au1000_close() and free_irq() on the stack. Drop aup->lock before freeing the IRQ. The protected close-time work still stops the device and queue before IRQ teardown, but the sleepable IRQ core path now runs outside the spinlocked section.
Title		net: au1000: move free_irq out of the close-time spinlocked section
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/4536667fba8ddbaff2f2a135080ae6aabf737b5e https://git.kernel.org/stable/c/f48763beab4eea41fc480c9702ec6eebe8d75e4f https://git.kernel.org/stable/c/fc2233f1ab2a1ca562869bca6987d7477671388c

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-09-24T16:02:52.078Z

Updated: 2026-10-03T10:57:48.033Z

Reserved: 2026-09-18T17:59:28.791Z

Link: CVE-2026-93815

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-09-24T17:17:15.010

Modified: 2026-10-03T11:17:51.403

Link: CVE-2026-93815

Redhat

Severity : Moderate

Publid Date: 2026-09-24T00:00:00Z

Links: CVE-2026-93815 - Bugzilla

OpenCVE Enrichment

Updated: 2026-10-01T20:00:12Z

Weaknesses

CWE-821
Incorrect Synchronization

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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