CVE-2026-90291

module/dups: Fix use-after-free in kmod_dup_req lifetime handling

Published Sep 17, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

module/dups: Fix use-after-free in kmod_dup_req lifetime handling

The kmod dups code uses RCU to ensure that a kmod_dup_req instance is freed
only after it is no longer referenced. When releasing an instance, the
kmod_dup_request_delete() function removes the kmod_dup_req from the
dup_kmod_reqs list, waits via synchronize_rcu() and finally frees it.
However, this doesn't work correctly because parallel users referencing the
instance in kmod_dup_request_exists_wait() don't enter an RCU read-side
critical section. This can result in a use-after-free.

The kmod_dup_request_exists_wait() function may need to hold a valid
reference to a kmod_dup_req instance across a blocking wait until the
corresponding modprobe command completes. This makes it unsuitable for RCU.

Fix the issue by changing the lifecycle management of kmod_dup_req to use
reference counting.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9022-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9023-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9024-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9025-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9026-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9039-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-9040-1 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9066-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-416
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: module/dups: Fix use-after-free in kmod_dup_req lifetime handling The kmod dups code uses RCU to ensure that a kmod_dup_req instance is freed only after it is no longer referenced. When releasing an instance, the kmod_dup_request_delete() function removes the kmod_dup_req from the dup_kmod_reqs list, waits via synchronize_rcu() and finally frees it. However, this doesn't work correctly because parallel users referencing the instance in kmod_dup_request_exists_wait() don't enter an RCU read-side critical section. This can result in a use-after-free. The kmod_dup_request_exists_wait() function may need to hold a valid reference to a kmod_dup_req instance across a blocking wait until the corresponding modprobe command completes. This makes it unsuitable for RCU. Fix the issue by changing the lifecycle management of kmod_dup_req to use reference counting.
Title module/dups: Fix use-after-free in kmod_dup_req lifetime handling
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 21, 2026, 12:50 PM
Reserved
Sep 11, 2026, 7:38 PM
Status
Received
Published
Sep 17, 2026, 5:17 PM
Modified
Oct 21, 2026, 1:20 PM