CVE-2023-6546: Linux Kernel GSM Multiplexing Race Condition Local Privilege Escalation Vulnerability

First published: Thu Dec 21 2023(Updated: )

A race condition was found in the GSM 0710 tty multiplexor (drivers/tty/n_gsm.c) in the Linux kernel. The flaw occurs when two threads execute the GSMIOC_SETCONF ioctl on the same tty file descriptor with the gsm line discipline enabled and leads to a use-after-free on a struct gsm_dlci while restarting the gsm mux. A local unprivileged user could use this vulnerability to escalate their privileges on the system. ZDI Security Advisory: <a href="https://www.zerodayinitiative.com/advisories/ZDI-CAN-20527">https://www.zerodayinitiative.com/advisories/ZDI-CAN-20527</a> Upstream fix: <a href="https://github.com/torvalds/linux/commit/3c4f8333b582487a2d1e02171f1465531cde53e3">https://github.com/torvalds/linux/commit/3c4f8333b582487a2d1e02171f1465531cde53e3</a>

Credit: secalert@redhat.com

Affected Software	Affected Version	How to fix
Linux kernel
redhat/kernel	<6.5	6.5
Linux Linux kernel	<6.5
Linux Linux kernel	=6.5-rc1
Linux Linux kernel	=6.5-rc2
Linux Linux kernel	=6.5-rc3
Linux Linux kernel	=6.5-rc4
Linux Linux kernel	=6.5-rc5
Linux Linux kernel	=6.5-rc6
Fedoraproject Fedora	=39
Redhat Enterprise Linux	=8.0
Redhat Enterprise Linux	=9.0
IBM QRadar SIEM	<=7.5 - 7.5.0 UP8 IF01