# CVE-2026-72149: dmaengine: tegra: Fix burst size calculation

> A flaw in the Tegra GPC DMA driver causes system hangs during UART transfers with non-aligned lengths, requiring a kernel patch to resolve.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72149, DEBIAN-CVE-2026-72149, GHSA-jjfr-vvvg-vj2f, UBUNTU-CVE-2026-72149

## What is CVE-2026-72149?

CVE-2026-72149 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

dmaengine: tegra: Fix burst size calculation

Currently, the Tegra GPC DMA hardware requires the transfer length to
be a multiple of the max burst size configured for the channel. When a
client requests a transfer where the length is not evenly divisible by
the configured max burst size, the DMA hangs with partial burst at
the end.

Fix this by reducing the burst size to the largest power-of-2 value
that evenly divides the transfer length. For example, a 40-byte
transfer with a 16-byte max burst will now use an 8-byte burst
(40 / 8 = 5 complete bursts) instead of causing a hang.

This issue was observed with the PL011 UART driver where TX DMA
transfers of arbitrary lengths were stuck.

## Which versions are affected by CVE-2026-72149?


## How do I fix CVE-2026-72149?

Apply the vendor's patch.

## Is CVE-2026-72149 being exploited?

There is no known exploitation of CVE-2026-72149 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72149 and fix it if it is affected.

What it is: CVE-2026-72149 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72149 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-72149/ (Markdown: https://insights.sbomify.com/CVE-2026-72149/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72149
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72149
- OSV: https://osv.dev/vulnerability/CVE-2026-72149

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72149/
Summaries are generated and may contain mistakes; the official description above is the record.