Linux Kernel up to 6.12.109/6.18.50/7.2.4 Buffer iio_device_put use after free

CVSS Meta Temp Score
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CTI Interest Score
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8.6$5k-$25k0.44

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.109/6.18.50/7.2.4. It has been rated as very critical. Impacted is the function iio_device_put of the component Buffer. The manipulation leads to use after free. This vulnerability is traded as CVE-2026-89942. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.12.109/6.18.50/7.2.4. This issue affects the function iio_device_put of the component Buffer. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix potential use-after-free in anonymous buffer release An anonymous buffer handle holds a reference to the underlying IIO device. The reference is dropped in the buffer handle's release function. If the device has been removed, either through unbind or hot-unplug, the buffer handle might hold the last reference. The release function takes the mutex for the buffer using a guard, which means the unlock happens after all the code in the function, including `iio_device_put()`. If the anonymous buffer holds the last reference this might free both the IIO device and the buffer, which contains the mutex, leading to use-after-free when the mutex is unlocked. Fix this by using a scoped guard just around the buffer dmabuf list access, making sure the mutex is unlocked before releasing the IIO device. Version 10 of the patch that introduced this issue used this exact scheme of first unlocking and then dropping the reference [1]. During review it was suggested to use a guard instead, and version 11 made that change [2].

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-89942 since 09/11/2026. The exploitation is known to be easy. The attack may be initiated remotely. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/16/2026).

Upgrading to version 6.12.110, 6.18.51, 7.2.5 or 7.3-rc1 eliminates this vulnerability. Applying the patch ab53077511cde811bf3ee219426c522329c41226/f1f8f0e8e0af9cae8150658dc7bb51332f984893/6d4bdbf7bad63e759bf20259c527f69a1209e3dd/6288b593e76eb10329326f2cd51e32557203b9e5 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.0
VulDB Meta Temp Score: 8.6

VulDB Base Score: 9.0
VulDB Temp Score: 8.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.110/6.18.51/7.2.5/7.3-rc1
Patch: ab53077511cde811bf3ee219426c522329c41226/f1f8f0e8e0af9cae8150658dc7bb51332f984893/6d4bdbf7bad63e759bf20259c527f69a1209e3dd/6288b593e76eb10329326f2cd51e32557203b9e5

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89942 (🔒)
GCVE (CVE): GCVE-0-2026-89942
GCVE (VulDB): GCVE-100-405839

Entryinfo

Created: 09/16/2026 15:17
Changes: 09/16/2026 15:17 (59)
Complete: 🔍
Cache ID: 216::103

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