---
id: "CVE-2026-99185"
kind: "vulnerability"
aliases: ["CVE-2026-99185"]
title: "Linux kernel FireWire: race condition causes use-after-free in transactions"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["firewire", "linux-kernel", "runtime", "self-hosted"]
not_affected_if: ["firewire-driver-not-loaded", "no-firewire-hardware"]
published_at: "2026-10-28T11:17:39+00:00"
first_seen_at: "2026-10-28T11:32:37+00:00"
updated_at: "2026-10-28T11:35:19+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99185", "first_seen_at": "2026-10-28T11:32:37+00:00"}]
---

# Linux kernel FireWire: race condition causes use-after-free in transactions

A race between the FireWire response handler and the split-transaction timeout callback lets both process the same transaction entry. The result is a use-after-free on the initiator side, 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 commit fixing the firewire split transaction race (the fix ensures the response handler skips entries when timer_delete() returns zero).

## Timeline

- 2026-10-28T11:32:37+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99185

## From the sources

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

firewire: core: fix race condition in split transaction handling

For a split transaction, either fw_core_handle_response() or
split_transaction_timeout_callback() may manipulate the same transaction
entry in the pending transaction list. The return value of timer_delete()
is used to determine which function handles the entry. If the transaction
is a split transaction and timer_delete() returns zero, the timeout
callback may already be running. In this case, the response handler must
leave the entry in the list for the timeout callback to remove.

A previous code refactoring broke this behavior, introducing a race
condition in which both functions could process the same transaction.
This could lead to a use-after-free on the transaction initiator side.

Fix the regression by ensuring that the response handler does not process
the transaction when timer_delete() returns zero. The timeout callback is
responsible for removing the entry from the pending transaction list.

---

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