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High7.0Red Hat Linux

High [CVE-2023-6546] Kernel: gsm multiplexing race condition leads to privilege escalation

This high-severity Red Hat Linux advisory covers CVE-2023-6546 affecting Red Hat Enterprise Linux 8.2 Advanced Update Support, Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.4 Telecommunications Update Service.

CVE-2023-6546 Published Dec 21, 2023Updated by vendor Aug 6, 2026
Affected products & platforms
Red Hat LinuxRed Hat Enterprise Linux
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Summary

A race condition was found in the GSM 0710 tty multiplexor in the Linux kernel. This issue occurs when two threads execute the GSMIOC_SETCONF ioctl on the same tty file descriptor with the gsm line discipline enabled, and can lead to a use-after-free problem on a struct gsm_dlci while restarting the gsm mux.

This could allow a local unprivileged user to escalate their privileges on the system.

Affected products named by the advisory: Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 8.2 Advanced Update Support; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support; Red Hat Enterprise Linux 8.4 Telecommunications Update Service; and 8 more.

Affected products named by the advisory: Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions; Red Hat Enterprise Linux 8.6 Extended Update Support; Red Hat Enterprise Linux 8.8 Extended Update Support; Red Hat Enterprise Linux 9.0 Extended Update Support; and 3 more.

Affected products named by the advisory: Red Hat Enterprise Linux 9.2 Extended Update Support; Red Hat Virtualization 4 for Red Hat Enterprise Linux 8; RHOL-5.7-RHEL-8.

Affected versions

No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.

Official advisory · medium-confidence parse· fetched 50 minutes ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.

Official advisory · medium-confidence parse· fetched 50 minutes ago·verify at source

Mitigation

The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.

Official advisory · medium-confidence parse· fetched 50 minutes ago·verify at source

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