CVE Catalog

CVE-2025-39790

HighCVSS 8.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

4th percentile - higher than 4% of all known CVEs

Summary

A vulnerability was found in the Linux kernel's MHI host driver (bus: mhi: host), where a remote device can send an event pointing to an unexpected TRE (Transfer Ring Element). This can lead to a double-free memory buffer when the host processes events in an incorrect order.

Risk Assessment

The risk includes potential kernel memory corruption, which could result in system crash or privilege escalation by an attacker-controlled remote device.

Recommendation

Immediately update the Linux kernel to a version containing the fix commit (commit 6f18d174b73d or later). Also ensure the MHI EP driver is properly updated.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS