SB20261022360 - Use-after-free in Linux kernel tty_port_tty_vhangup() and tty_port_hangup() in drivers/tty/tty_port.c

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-98752)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service by triggering a use-after-free or NULL-pointer dereference in the Linux kernel.

The vulnerability exists due to a use-after-free caused by missing synchronization in tty_port_tty_vhangup() and tty_port_hangup() when concurrent hangups overlap with port deregistration and resource teardown. A local user can trigger racing ioctl or hangup operations during teardown to access resources after they have been freed or encounter a NULL-pointer dereference, potentially causing a kernel crash.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/017b18addbe8dcace1a569a00d40ed1ba1e03f4c
• https://git.kernel.org/stable/c/6b7be3b9b857947e9c1338d4919d4ebd3b75e907
• https://git.kernel.org/stable/c/6d1a984afc3ca477dab3e51ec806671d443ad524
• https://git.kernel.org/stable/c/b48820de8c1a596c5b99775524dfce73c6576c5d
• https://git.kernel.org/stable/c/ce220b4cdf62f73db0c1940f968eb33b9899fdd0