CVE-2025-71285

What the bug is

MHI stack offers the 'auto_queue' feature, which allows the MHI stack to auto queue the buffers for the RX path (DL channel). Though this feature simplifies the client driver design, it introduces race between the client drivers and the MHI stack. For instance, with auto_queue, the 'dl_callback' for the DL channel may get called before the client driver is fully probed. This means, by the time the dl_callback gets called, the client driver's structures might not be initialized, leading to NULL ptr dereference. Currently, the drivers have to workaround this issue by initializing the internal structures before calling mhi_prepare_for_transfer_autoqueue(). But even so, there is a chance that the client driver's internal code path may call the MHI queue APIs before mhi_prepare_for_transfer_autoqueue() is called, leading to similar NULL ptr dereference. This issue has been reported on the Qcom X1E80100 CRD machines affecting boot. So to properly fix all these races, drop the MHI 'auto_queue' feature altogether and let the client driver (QRTR) manage the RX buffers manually. In the QRTR driver, queue the RX buffers based on the ring length during probe and recycle the buffers in 'dl_callback' once they are consumed. This also warrants removing the setting of 'auto_queue' flag from controller drivers. Currently, this 'auto_queue' feature is only enabled for IPCR DL channel. So only the QRTR client driver requires the modification.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/accel/qaic/mhi_controller.c
drivers/bus/mhi/host/pci_generic.c
drivers/net/wireless/ath/ath11k/mhi.c
drivers/net/wireless/ath/ath12k/mhi.c
net/qrtr/mhi.c

What this is

QUALCOMM CLOUD AI (QAIC) DRIVERMAINTAINERS section matched on drivers/accel/qaic/ · linux-arm-msm@vger.kernel.org · Supported

Kernel module

qaic

Check it on the machine

grep -wE 'CONFIG_DRM_ACCEL|CONFIG_DRM_ACCEL_QAIC|CONFIG_MHI_BUS_PCI_GENERIC' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w qaic

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian does not build this code in 3 releases. It does build it in 1 release, so the answer depends on which release the machine runs.

• bookwormm
• trixie, forky, sidn

m

a loadable module on every flavour - check lsmod, can be blacklisted

n

not enabled on any flavour - this release does not build the code

Build switches

CONFIG_DRM_ACCEL, CONFIG_DRM_ACCEL_QAIC, CONFIG_MHI_BUS_PCI_GENERIC

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-05-06 (5 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.13%, higher than 2.1% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/accel

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
5.17	6.18.17	7bdff9b9b0c6
5.17	6.19.6	8c464e00e075
5.17	7.0	51731792a25c
5.15.63	0	0