CVE-2026-53181
In the Linux kernel, the following vulnerability has been resolved: vsock/vmci: fix sk_ack_backlog leak on failed handshake When vmci_transport_recv_connecting_server() returns an error, vmci_transport_recv_listen() calls vsock_remove_pending() but…
Does this matter?
Lower severity and a low EPSS score (0.12%). Track it; it rarely justifies an emergency change on its own.
Description
In the Linux kernel, the following vulnerability has been resolved: vsock/vmci: fix sk_ack_backlog leak on failed handshake When vmci_transport_recv_connecting_server() returns an error, vmci_transport_recv_listen() calls vsock_remove_pending() but never calls sk_acceptq_removed(). This leaves sk_ack_backlog incremented permanently. Repeated handshake failures (malformed packets, queue pair alloc failure, event subscribe failure) cause sk_ack_backlog to climb toward sk_max_ack_backlog. Once it reaches the limit the listener permanently refuses all new connections with -ECONNREFUSED, a silent denial of service requiring a process restart to recover. The two existing sk_acceptq_removed() calls in af_vsock.c do not cover this path: line 764 checks vsock_is_pending() which returns false after vsock_remove_pending(), and line 1889 is only reached on successful accept(). Fix by balancing sk_acceptq_added() with sk_acceptq_removed() on the error path.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.12% probability · 2th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-401
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/22c587aa3ab1ab5264daff3ec32136fd30436c13Patch
- https://git.kernel.org/stable/c/9698582a4dd9c4a05889d7db96d4c0edc9e69cacPatch
- https://git.kernel.org/stable/c/ba9ad6015937a5e46ba1a31370e3efdec8abbdccPatch
- https://git.kernel.org/stable/c/bcb275626055df7f8f947f1a349754b4004d9a15Patch
- https://git.kernel.org/stable/c/c05fa14db43ebef3bd862ca9d073981c0358b3f0Patch
- https://git.kernel.org/stable/c/cf7090e255d74c4b61c51f8ede9fcacdd8393b5bPatch
- https://git.kernel.org/stable/c/dfd853197615d322d3a88dbcab91fc0fd2096219Patch
- https://git.kernel.org/stable/c/ea0b03d52881c12a8c634ea0d6cbfa61cefdb488Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.