CVE-2023-6546

Kernel: gsm multiplexing race condition leads to privilege escalation

HIGH
7
CVSS Score
Published: December 21, 2023 at 08:01 PM UTC
Updated: August 6, 2026 at 10:16 PM UTC
3 products affected across 3 vendorsLinux KernelFedoraEnterprise Linux

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Severity
HIGH7
Exploit prediction
EPSS 0.7%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Affected range stops below 6.5, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 0:4.18.0-193.136.1.el8_2 (unaffected)
Vendor states this is fixed in 0:4.18.0-305.134.1.el8_4 (unaffected)
Vendor states this is fixed in 0:4.18.0-305.134.1.rt7.210.el8_4 (unaffected)
Vendor states this is fixed in 0:4.18.0-372.93.1.el8_6 (unaffected)
Vendor states this is fixed in 0:4.18.0-477.55.1.el8_8 (unaffected)
Vendor states this is fixed in 0:4.18.0-513.24.1.el8_9 (unaffected)
Vendor states this is fixed in 0:4.18.0-513.24.1.rt7.326.el8_9 (unaffected)
Vendor states this is fixed in 0:5.14.0-284.55.1.el9_2 (unaffected)
Vendor states this is fixed in 0:5.14.0-284.55.1.rt14.340.el9_2 (unaffected)
Vendor states this is fixed in 0:5.14.0-427.13.1.el9_4 (unaffected)
Vendor states this is fixed in 0:5.14.0-70.93.1.rt21.165.el9_0 (unaffected)
Vendor states this is fixed in 0:5.14.0-70.93.2.el9_0 (unaffected)
Vendor states this is fixed in 6 (unaffected)
Vendor states this is fixed in 7 (unaffected)
Vendor states this is fixed in 8 (unaffected)

References (31)

CVSS

7HIGHredhat
Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-416CWE-362CWE-366

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