Linux Kernel up to 6.16.3 xfer_cb double free

CVSS Meta Temp Score
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CTI Interest Score
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7.3$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 5.15.189/6.1.148/6.6.102/6.12.43/6.16.3. The impacted element is the function xfer_cb. Executing a manipulation can lead to double free. The identification of this vulnerability is CVE-2025-39790. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 5.15.189/6.1.148/6.6.102/6.12.43/6.16.3. This vulnerability affects the function xfer_cb. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: host: Detect events pointing to unexpected TREs When a remote device sends a completion event to the host, it contains a pointer to the consumed TRE. The host uses this pointer to process all of the TREs between it and the host's local copy of the ring's read pointer. This works when processing completion for chained transactions, but can lead to nasty results if the device sends an event for a single-element transaction with a read pointer that is multiple elements ahead of the host's read pointer. For instance, if the host accesses an event ring while the device is updating it, the pointer inside of the event might still point to an old TRE. If the host uses the channel's xfer_cb() to directly free the buffer pointed to by the TRE, the buffer will be double-freed. This behavior was observed on an ep that used upstream EP stack without 'commit 6f18d174b73d ("bus: mhi: ep: Update read pointer only after buffer is written")'. Where the device updated the events ring pointer before updating the event contents, so it left a window where the host was able to access the stale data the event pointed to, before the device had the chance to update them. The usual pattern was that the host received an event pointing to a TRE that is not immediately after the last processed one, so it got treated as if it was a chained transaction, processing all of the TREs in between the two read pointers. This commit aims to harden the host by ensuring transactions where the event points to a TRE that isn't local_rp + 1 are chained. [mani: added stable tag and reworded commit message]

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2025-39790 since 04/16/2025. The exploitation appears to be difficult. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 01/16/2026).

The vulnerability scanner Nessus provides a plugin with the ID 264762 (Linux Distros Unpatched Vulnerability : CVE-2025-39790), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4 or 6.17-rc1 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (264762), EUVD (EUVD-2025-28923) and CERT Bund (WID-SEC-2025-2040). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Fedora Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel
  • Proxmox Virtual Environment
  • Proxmox Backup Server
  • Dell Secure Connect Gateway
  • IBM QRadar SIEM

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.4
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.1
VulDB Temp Score: 6.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 264762
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-39790

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.190/6.1.149/6.6.103/6.12.44/6.16.4/6.17-rc1
Patch: git.kernel.org

Timelineinfo

04/16/2025 CVE reserved
09/11/2025 +148 days Advisory disclosed
09/11/2025 +0 days VulDB entry created
01/16/2026 +127 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39790 (🔒)
GCVE (CVE): GCVE-0-2025-39790
GCVE (VulDB): GCVE-100-323704
EUVD: 🔒
CERT Bund: WID-SEC-2025-2040 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 09/11/2025 19:39
Updated: 01/16/2026 22:20
Changes: 09/11/2025 19:39 (57), 09/12/2025 00:54 (1), 09/13/2025 08:16 (7), 09/14/2025 19:47 (2), 11/08/2025 21:47 (1), 11/16/2025 01:38 (1), 01/16/2026 22:20 (11)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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