CVE-2026-90000

What the bug is

The hid-rmi driver sizes its writeReport/readReport buffer purely from the report descriptor supplied by the device, with no minimum bound: data->input_report_size = hid_report_len(input_report); data->output_report_size = hid_report_len(output_report); alloc_size = data->output_report_size + data->input_report_size; data->writeReport = devm_kzalloc(&hdev->dev, alloc_size, GFP_KERNEL); data->readReport = data->writeReport + data->output_report_size; but then reads and writes fixed offsets into it. A device declaring a 1-byte output and a 1-byte input report makes hid_report_len() return 2 for each, so alloc_size is 4, while rmi_set_page() -- reached unconditionally at probe time through rmi_input_configured() -- stores writeReport[4] and rmi_hid_read_block() stores writeReport[0..5]. Since readReport lives at writeReport + output_report_size, those stores also corrupt the window the next reply is parsed out of. The read path is worse: the copy length comes from readReport[1], which the device fills in and can be up to 255, and the copy starts at &readReport[2] with no regard for input_report_size, so it runs past the end of the allocation into adjacent slab objects. This does not even need a lying device -- rmi_f01_probe() issues a fixed 21-byte register read, so any device declaring an input report smaller than 23 bytes reads out of bounds even when it answers truthfully. Those bytes become the register values the RMI core acts on: rmi_f01_probe() prints them to the kernel log as the product id and exports them through the mode 0444 sysfs attribute of the same name, and rmi_driver_set_irq_bits() sends them back to the device as the interrupt mask, so an undersized report descriptor leaks heap contents both to unprivileged userspace and to the device itself. The write path has no bound either: rmi_hid_write_block() copies an unbounded len to &writeReport[4], and the largest caller a device can drive at probe time is rmi_driver_set_irq_bits(), whose length is derived from the interrupt source counts the device declares in its Page Description Table. Finally, the read loop cannot terminate on a zero-length reply: such a reply copies nothing and advances neither bytes_read nor bytes_needed, and because a reply did arrive the one second wait_event_timeout() does not fire either, so a device answering 0 forever keeps the loop running inside the probe worker with page_mutex held. khungtaskd does not notice, because every reply wakes the task. Reject reports too small for what the driver builds -- 6 output bytes for the write reports and 3 input bytes for the read handshake -- at probe time, clamp the write and the read copy to the report sizes the device declared, and treat a zero-length reply as an error. A device refused this way is started as an ordinary HID device, like one that does not carry the RMI report ids at all. RMI_DEVICE must not be left set in device_flags on that path, because rmi_input_configured() would then run the RMI setup and reach rmi_set_page(), which writes the writeReport buffer the refusal just skipped allocating. The bit can arrive set: rmi_probe() copies id->driver_data into device_flags before the report checks, and a bind through the new_id sysfs attribute can supply driver_data with RMI_DEVICE (BIT(0)) set. Strip the bit where driver_data is copied, so RMI_DEVICE keeps meaning exactly "this probe validated the reports"; the three jumps to start that predate this patch are covered as well. The error path also clears RMI_READ_DATA_PENDING on its way out, because that flag is what the wait at the top of the loop tests: leaving it set would make every later wait_event_timeout() return immediately on the stale reply and kill the read path for the rest of the device's life. Clamping does not regress working hardware: the read loop already handles ---truncated---

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/hid/hid-rmi.c

What this is

HID CORE LAYERMAINTAINERS section matched on drivers/hid/ · linux-input@vger.kernel.org · Maintained

Kernel module

hid_rmi

Check it on the machine

grep -wE 'CONFIG_HID|CONFIG_HID_RMI|CONFIG_HID_SUPPORT' /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 hid_rmi

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 builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookworm, trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_HID, CONFIG_HID_RMI, CONFIG_HID_SUPPORT

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

2026-09-16 (33 days ago)source

CVSS

8.8 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it

Attack vector

adjacent network (AV:A)source

EPSS

0.35%, higher than 27.0% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/hid

Upstream fixes

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

Introduced	Fixed in	Commit
3.16	5.10.270	fba600d82459
3.16	5.15.221	056ef8e6700b
3.16	6.1.188	183da103022e
3.16	6.6.157	a8be8bbf0952
3.16	6.12.110	ab2958e0c94e
3.16	6.18.51	f4cb9c4556dc
3.16	7.2.5	48934c292741
3.16	7.3	4956993bb3be

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