---
id: "CVE-2026-98748"
kind: "vulnerability"
aliases: ["CVE-2026-98748"]
title: "Linux kernel: serial BCM7271 driver use-after-free on UART removal"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["broadcom-stb", "embedded", "linux-kernel", "package"]
not_affected_if: ["hardware-flow-control-disabled", "no-bcm7271-uart"]
published_at: "2026-10-18T16:17:28+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:16:58+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98748", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel: serial BCM7271 driver use-after-free on UART removal

In the Linux kernel's BCM7271 8250 serial driver, a receive-timeout interrupt during device removal can re-arm a timer after its private data has been freed. The timer callback then runs on freed memory, which can crash the kernel or be abused for memory corruption.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- Update to a Linux kernel release that includes the upstream fix 'serial: 8250_bcm7271: fix use-after-free in brcmuart_remove()' (the fixed version is not named in the sources)

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98748

## From the sources

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

serial: 8250_bcm7271: fix use-after-free in brcmuart_remove()

brcmuart_handle_irq() starts priv->hrt to work around a receive-timeout
quirk of the 8250 core when hardware flow control is enabled; the timer
callback brcmuart_hrtimer_func() dereferences priv.

brcmuart_remove() cancels the hrtimer before it unregisters the port, so
a receive-timeout interrupt that arrives in between re-arms the timer.
After devm frees priv, the callback runs on freed memory.

Unregister the port before cancelling the hrtimer.
serial8250_unregister_port() shuts the port down and frees its IRQ, so
brcmuart_handle_irq() can no longer restart the timer, and the final
hrtimer_cancel() drains any timer that was armed before or during the
unregister.

This issue was found by an in-house static analysis tool.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_