CVE-2025-23151

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

bus: mhi: host: Fix race between unprepare and queue_buf

A client driver may use mhi_unprepare_from_transfer() to quiesce incoming data during the client driver's tear down. The client driver might also be processing data at the same time, resulting in a call to mhi_queue_buf() which will invoke mhi_gen_tre(). If mhi_gen_tre() runs after mhi_unprepare_from_transfer() has torn down the channel, a panic will occur due to an invalid dereference leading to a page fault.

This occurs because mhi_gen_tre() does not verify the channel state after locking it. Fix this by having mhi_gen_tre() confirm the channel state is valid, or return error to avoid accessing deinitialized data.

[mani: added stable tag]

Red Hat rates this flaw as having low security impact. A race condition was found in the Linux kernel MHI (Modem Host Interface) host bus stack. When a client driver calls mhi_unprepare_from_transfer() to quiesce incoming data during its teardown while it is still processing data, a concurrent call to mhi_queue_buf() may invoke mhi_gen_tre(). If mhi_gen_tre() runs after the channel has already been torn down and does not verify the channel state after locking it, an invalid dereference occurs that causes a page fault and a kernel panic, resulting in denial of service. Exploiting this race requires local privileged access and a narrow timing window, and the impact is limited to availability, which is why Red Hat assesses this flaw as low severity (CVSS 4.1). This is notably lower than the generic 7.8 score in the upstream CVE record, which does not account for the specific preconditions and availability-only consequence of this flaw. Red Hat Enterprise Linux 9 and 10 (kernel and kernel-rt) and Red Hat In-Vehicle OS 1 are affected; the fix is currently deferred for these streams given the low impact and the difficulty of triggering the race, and the residual risk is a potential kernel panic (denial of service) if a privileged local actor can race client-driver teardown. Red Hat Enterprise Linux 6, 7, and 8 and the Hosted OpenShift (ARO/OSD) streams are not affected because the vulnerable code is not present in those products.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.