---
id: "CVE-2026-98777"
kind: "vulnerability"
aliases: ["CVE-2026-98777"]
title: "Linux kernel: binder leaks file references when superseding frozen transactions"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["android", "binder", "linux-kernel", "runtime"]
not_affected_if: ["binder-not-in-use"]
published_at: "2026-10-18T16:17:31+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:15:25+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98777", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel: binder leaks file references when superseding frozen transactions

When a binder transaction is superseded in a frozen process, its file descriptor fixup entries are freed without releasing their file references. The leaked struct file objects stay pinned after process exit and can accumulate until the system runs out of file handles.

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

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98777

## From the sources

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

binder: fix leaked fd fixups on TF_UPDATE_TXN supersede

When a TF_UPDATE_TXN transaction supersedes a pending async transaction
in a frozen process, the outdated transaction is freed with kfree()
directly. This skips binder_free_txn_fixups(), leaking all
binder_txn_fd_fixup entries and their fget()'d struct file references.

The leaked file refcounts never reach zero, so the struct file objects
are permanently pinned in memory. They survive process exit and
accumulate across invocations until file-max exhaustion.

Every other transaction cleanup path (binder_free_transaction(),
binder_transaction() error paths, binder_release_work()) correctly
calls binder_free_txn_fixups(). Add the missing call before kfree()
in the t_outdated cleanup block.

---

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