Описание
In the Linux kernel, the following vulnerability has been resolved:
virtio/vsock: Fix accept_queue memory leak
As the final stages of socket destruction may be delayed, it is possible
that virtio_transport_recv_listen() will be called after the accept_queue
has been flushed, but before the SOCK_DONE flag has been set. As a result,
sockets enqueued after the flush would remain unremoved, leading to a
memory leak.
vsock_release
__vsock_release
lock
virtio_transport_release
virtio_transport_close
schedule_delayed_work(close_work)
sk_shutdown = SHUTDOWN_MASK
(!) flush accept_queue
release
virtio_transport_recv_pkt
vsock_find_bound_socket
lock
if flag(SOCK_DONE) return
virtio_transport_recv_listen
child = vsock_create_connected
(!) vsock_enqueue_accept(child)
release
close_work
lock
virtio_transport_do_close
set_flag(SOCK_DONE)
virtio_transport_remove_sock
vsock_remove_sock
vsock_remove_bound
release
Introduce a sk_shutdown check to disallow vsock_enqueue_accept() during
socket destruction.
unreferenced object 0xffff888109e3f800 (size 2040):
comm "kworker/5:2", pid 371, jiffies 4294940105
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
28 00 0b 40 00 00 00 00 00 00 00 00 00 00 00 00 (..@............
backtrace (crc 9e5f4e84):
[] kmem_cache_alloc_noprof+0x2c1/0x360
[] sk_prot_alloc+0x30/0x120
[] sk_alloc+0x2c/0x4b0
[] __vsock_create.constprop.0+0x2a/0x310
[] virtio_transport_recv_pkt+0x4dc/0x9a0
[] vsock_loopback_work+0xfd/0x140
[] process_one_work+0x20c/0x570
[] worker_thread+0x1bf/0x3a0
[] kthread+0xdd/0x110
[] ret_from_fork+0x2d/0x50
[] ret_from_fork_asm+0x1a/0x30
A flaw was found in the Linux kernel's virtio/vsock subsystem. Due to a race condition during socket destruction, incoming connection requests can be added to the queue after it has already been cleared, leaving unreleased sockets in memory. A local attacker could exploit this timing issue to cause a kernel memory leak, potentially exhausting system resources and leading to a Denial of Service (DoS).
Меры по смягчению последствий
Summary:
Prevent the vsock and vmw_vsock_virtio_transport kernel modules from loading if virtual socket communication is not required.
Command Instructions:
- Create a configuration file to prevent loading the modules:
- Unload the modules from the running system if currently loaded and not in use:
Caveats: Disabling these modules halts virtual socket communication (AF_VSOCK) between the host hypervisor and virtual machines. Virtualization features, guest agents, and container utilities that rely on VSOCK will fail to operate. Warning: If the modules are in active use and cannot be unloaded dynamically, a system reboot is required for the configuration to take effect.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | ||
| Red Hat Enterprise Linux 8 | kernel | Will not fix | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Will not fix | ||
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:20518 | 11.11.2025 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:20518 | 11.11.2025 |
Показывать по
Дополнительная информация
Статус:
EPSS
6.1 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: virtio/vsock: Fix accept_queue memory leak As the final stages of socket destruction may be delayed, it is possible that virtio_transport_recv_listen() will be called after the accept_queue has been flushed, but before the SOCK_DONE flag has been set. As a result, sockets enqueued after the flush would remain unremoved, leading to a memory leak. vsock_release __vsock_release lock virtio_transport_release virtio_transport_close schedule_delayed_work(close_work) sk_shutdown = SHUTDOWN_MASK (!) flush accept_queue release virtio_transport_recv_pkt vsock_find_bound_socket lock if flag(SOCK_DONE) return virtio_transport_recv_listen child = vsock_create_connected (!) vsock_enqueue_accept(child) release close_work lock virtio_transport_do_close set_flag(SOCK_DONE) virtio_transport_remove_sock vsock_remove_sock vsock_remove_bound release Introduce a sk_shutdown check to disallow vsock_enqueue_accept() during socket destruc...
In the Linux kernel, the following vulnerability has been resolved: virtio/vsock: Fix accept_queue memory leak As the final stages of socket destruction may be delayed, it is possible that virtio_transport_recv_listen() will be called after the accept_queue has been flushed, but before the SOCK_DONE flag has been set. As a result, sockets enqueued after the flush would remain unremoved, leading to a memory leak. vsock_release __vsock_release lock virtio_transport_release virtio_transport_close schedule_delayed_work(close_work) sk_shutdown = SHUTDOWN_MASK (!) flush accept_queue release virtio_transport_recv_pkt vsock_find_bound_socket lock if flag(SOCK_DONE) return virtio_transport_recv_listen child = vso
In the Linux kernel, the following vulnerability has been resolved: v ...
In the Linux kernel, the following vulnerability has been resolved: virtio/vsock: Fix accept_queue memory leak As the final stages of socket destruction may be delayed, it is possible that virtio_transport_recv_listen() will be called after the accept_queue has been flushed, but before the SOCK_DONE flag has been set. As a result, sockets enqueued after the flush would remain unremoved, leading to a memory leak. vsock_release __vsock_release lock virtio_transport_release virtio_transport_close schedule_delayed_work(close_work) sk_shutdown = SHUTDOWN_MASK (!) flush accept_queue release virtio_transport_recv_pkt vsock_find_bound_socket lock if flag(SOCK_DONE) return virtio_transport_recv_listen child = ...
EPSS
6.1 Medium
CVSS3