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/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-401
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d3b91ac0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d3b90780> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2a1f92c80> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd319c74600> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d3b92980> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d3b90840> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd36b155500> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7fd36afa7840> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7fd36b7d4340> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7fd2d3b90400> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7fd34122e880> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7fd36afa5080> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7fd36b7d70c0> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* |