CVE-2026-98742

Received Received - Intake

Race Condition in Linux Kernel ALSA Sequencer Compat Port-Info Handling

Publication date: 2026-10-18

Last updated on: 2026-10-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Serialize compat port-info ioctls The native sequencer ioctl path serializes handler calls with client->ioctl_mutex, but the translated port-info compat path invokes the same handlers through snd_seq_kernel_client_ctl() without taking that mutex. This lets concurrent compat CREATE_PORT requests pass the port-count check before any request reaches the serialized insertion. The computed integer port index can then exceed the address field range and wrap to an existing index. Subsequent subscriber teardown can resolve the duplicate address to the wrong port and access a freed subscriber. Take ioctl_mutex while dispatching converted port-info requests, matching the native ioctl path. All translated port-info commands share this helper, so their accesses to the client port state are serialized as well.

CVSS Scores

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Meta Information

Published

2026-10-18

Last Modified

2026-10-19

Generated

2026-10-19

AI Q&A

2026-10-18

EPSS Evaluated

N/A

NVD

CVE-2026-98742

EUVD

EUVD-2026-103827

Affected Vendors & Products

Vendor	Product	Version / Range
Linux	Linux	b3defb791b26ea0683a93a4f49c77ec45ec96f10
Linux	Linux	b3defb791b26ea0683a93a4f49c77ec45ec96f10
Linux	Linux	b3defb791b26ea0683a93a4f49c77ec45ec96f10
Linux	Linux	b3defb791b26ea0683a93a4f49c77ec45ec96f10
Linux	Linux	d6693160906d55ba376bf0b88b7c129762170162
Linux	Linux	02cbce8576a31df8fca54aaec91ee081076bd79d
Linux	Linux	6aab3aa52366a0051e5abf8aae4616c42053fd8e
Linux	Linux	f8a38ab4cd9624fc5ac8a7f965c7b20f5b62c03c
Linux	Linux	623e5c8ae32b39cc8baea83478695dc624935318
Linux	Linux	e4ff9f294629b65df3f7982cd4faf86b2856b9d7
Linux	Linux	c3162384aed4cfe3f1a1f40041f3ba8cd7704d88
Linux	Linux	3.2.99
Linux	Linux	3.16.54
Linux	Linux	3.18.94
Linux	Linux	4.1.50
Linux	Linux	4.4.115
Linux	Linux	4.9.78
Linux	Linux	4.14.15
Linux	Linux	4.15

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a Linux kernel vulnerability where concurrent compat CREATE_PORT requests can bypass a port-count check due to missing synchronization. The integer port index may wrap around to an existing index, causing a freed subscriber to be accessed incorrectly.

Detection Guidance

This vulnerability is specific to the Linux kernel's ALSA sequencer subsystem and requires kernel-level inspection. Detection involves checking kernel version and ALSA module behavior. Use uname -a to verify kernel version and lsmod | grep snd_seq to confirm ALSA sequencer module is loaded.

Impact Analysis

An attacker could exploit this to cause memory corruption or denial of service by manipulating port indices. This may lead to system crashes or unauthorized access to freed memory regions.

Compliance Impact

This vulnerability does not directly impact compliance with GDPR, HIPAA, or similar standards as it is a low-level kernel issue affecting ALSA sequencer ioctl handling. No evidence suggests it leads to data breaches or unauthorized access that would violate these regulations.

Mitigation Strategies

Apply the latest kernel update from your Linux distribution to patch this issue. If immediate patching is not possible, disable the ALSA sequencer module temporarily with modprobe -r snd_seq. Monitor system logs for unusual port creation activity in /var/log/kern.log or journalctl -k.

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