PT-2025-46743 · Linux+5 · Linux Kernel+5
Published
2025-10-01
·
Updated
2026-03-14
·
CVE-2025-40186
CVSS v2.0
6.0
Medium
| Vector | AV:L/AC:H/Au:S/C:C/I:C/A:C |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The Linux kernel contains a flaw in the TCP implementation where calling
reqsk fastopen remove() within tcp conn request() can lead to a use-after-free and a refcount underflow. This occurs when a listener is closed while a TCP Fast Open (TFO) socket is being processed. Specifically, the issue arises because reqsk fastopen remove() is called with an invalid reqsk pointer, leading to a double-free of the request socket. The syzbot fuzzer reported this issue, resulting in a kernel panic.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
Use After Free
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Related Identifiers
Affected Products
Centos
Debian
Linuxmint
Linux Kernel
Red Hat
Ubuntu