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

drm/amd/display: fix division by zero in get_estimated_bw()

get_estimated_bw() divides by link->dpia_bw_alloc_config.bw_granularity,
which is zeroed by reset_bw_alloc_struct() and only populated once
DP_TUNNELING_BW_ALLOC_CAP_CHANGED has been handled.

link_dp_dpia_handle_bw_alloc_status(), the DPCD interrupt handler,
calls get_estimated_bw() whenever DP_TUNNELING_ESTIMATED_BW_CHANGED
is set, independently of whether DP_TUNNELING_BW_ALLOC_CAP_CHANGED
has ever fired for that link. A connected USB4/DPIA tunneling device
that reports an estimated-bandwidth change before ever reporting a
capability change drives a division by zero in this IRQ path.

link_dpia_send_bw_alloc_request() already guards the same
bw_granularity division; add the identical guard here rather than
introducing a new pattern.

(cherry picked from commit f2a961457c33dc34223aad5c9e8971de34a4eed3)
Published: 2026-09-16
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Wed, 16 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: fix division by zero in get_estimated_bw() get_estimated_bw() divides by link->dpia_bw_alloc_config.bw_granularity, which is zeroed by reset_bw_alloc_struct() and only populated once DP_TUNNELING_BW_ALLOC_CAP_CHANGED has been handled. link_dp_dpia_handle_bw_alloc_status(), the DPCD interrupt handler, calls get_estimated_bw() whenever DP_TUNNELING_ESTIMATED_BW_CHANGED is set, independently of whether DP_TUNNELING_BW_ALLOC_CAP_CHANGED has ever fired for that link. A connected USB4/DPIA tunneling device that reports an estimated-bandwidth change before ever reporting a capability change drives a division by zero in this IRQ path. link_dpia_send_bw_alloc_request() already guards the same bw_granularity division; add the identical guard here rather than introducing a new pattern. (cherry picked from commit f2a961457c33dc34223aad5c9e8971de34a4eed3)
Title drm/amd/display: fix division by zero in get_estimated_bw()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-16T10:33:35.281Z

Reserved: 2026-09-11T19:38:34.782Z

Link: CVE-2026-90035

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-16T11:17:16.690

Modified: 2026-09-16T11:17:16.690

Link: CVE-2026-90035

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses

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