Bug 2507196 (CVE-2026-64275)

Summary:	CVE-2026-64275 kernel: Input: elan_i2c - prevent division by zero and arithmetic underflow
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's Elan I2C touchpad driver. This vulnerability occurs when the driver receives invalid zero values for touchpad dimensions from device firmware or the device tree, or when a calculated width is too small. A local attacker with control over device input or a malicious device could exploit this to trigger a division-by-zero error, leading to a kernel panic and a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-25 10:10:04 UTC

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

Input: elan_i2c - prevent division by zero and arithmetic underflow

The Elan I2C touchpad driver queries the device for its physical
dimensions and trace counts to calculate the device resolution and width.
However, if the device firmware or device tree provides invalid zero
values for x_traces or y_traces, it results in a fatal division-by-zero
exception leading to a kernel panic during device probe.

Add checks to ensure these parameters are non-zero before performing
the division. If invalid trace values are detected, fall back to a safe
default of 1.

Additionally, prevent an arithmetic underflow in the touch reporting
logic. Previously, if the calculated or fallback width was smaller than
ETP_FWIDTH_REDUCE (90), the subtraction would underflow, resulting in a
massive unsigned integer being reported to userspace. Clamp the adjusted
width to a minimum of 0 to safely handle small physical dimensions and
fallback scenarios.

Completing the probe with safe fallback values ensures the sysfs nodes
are created, keeping the firmware update path intact so a recovery
firmware can be flashed to the device.

Comment 1 TEJ RATHI 2026-07-29 10:35:04 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072500-CVE-2026-64275-7f24@gregkh/T