Bug 2546485 (CVE-2026-98181)

Summary: CVE-2026-98181 kernel: drm/gud: fix out-of-bounds write in gud_plane_atomic_check()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 Generic USB Display (GUD) driver. An attacker connecting a specially crafted USB device advertising a maximum number of display properties can trigger an array indexing error during property validation. This flaw leads to an out-of-bounds memory write, which can result in a system crash causing a Denial of Service (DoS) or potentially lead to arbitrary code execution.
 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 2026-10-06 09:30:00 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/gud: fix out-of-bounds write in gud_plane_atomic_check()

The plane property loop uses req->properties[num_properties + i] as write
index while simultaneously incrementing `num_properties` inside the loop.
At iteration i, num_properties has also incremented by i, so the write
is done at `initial_num_properties + 2*i`, skipping every other index and
advancing by 2 per iteration.

With just 2 connector and 32 plane properties the last write happens at
index 64, one slot past the end of the 64-slot (indices 0–63)
allocation. A USB device can trigger OOB by advertising the maximum
number of properties.

Fix by dropping the redundant `+ i`; num_properties is already the correct
running index, as gud_connector_fill_properties() fills the preceding
slots.