Improper locking in Linux kernel - CVE-2026-64177
Published: July 20, 2026
Vulnerability identifier: #VU138458
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-64177
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper locking in pep_do_rcv() in net/phonet/pep.c when forwarding an skb to a child socket via sk_receive_skb(). A local user can trigger socket backlog processing that acquires the child socket lock with bottom halves enabled to cause a denial of service.
The issue can lead to an inconsistent lock state and a self-deadlock on the same CPU when packets are received for the same child socket.
How to mitigate CVE-2026-64177
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/02c04df84de709060f63e1d52ec67488c4f6f212
- https://git.kernel.org/stable/c/8420aa4900417797323dd567ba9d1512280c2dc3
- https://git.kernel.org/stable/c/84bc87beb4cd77670939b446326788e4c9b3db37
- https://git.kernel.org/stable/c/a3fc8f2dacd1c37325977fc1fbbf3d52141df99e
- https://git.kernel.org/stable/c/b2606c302d7f2b4ee48da05e32ed60aed1b0cd53
- https://git.kernel.org/stable/c/bd795f106b3889fb0706c6e4831c4b27e2b5666b
- https://git.kernel.org/stable/c/dbc81608e3a653dea6cf403f20cae35468b8ab9c
- https://git.kernel.org/stable/c/f08c45076e4fd8b0adbc5eb186d6e6a3e7350d7b