// For flags

CVE-2023-52842

virtio/vsock: Fix uninit-value in virtio_transport_recv_pkt()

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved:

virtio/vsock: Fix uninit-value in virtio_transport_recv_pkt()

KMSAN reported the following uninit-value access issue:

=====================================================
BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
kthread+0x3cc/0x520 kernel/kthread.c:388
ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was stored to memory at:
virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415
vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
kthread+0x3cc/0x520 kernel/kthread.c:388
ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was created at:
slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523
kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559
__alloc_skb+0x2fd/0x770 net/core/skbuff.c:650
alloc_skb include/linux/skbuff.h:1286 [inline]
virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58
virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387
vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
kthread+0x3cc/0x520 kernel/kthread.c:388
ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
Workqueue: vsock-loopback vsock_loopback_work
=====================================================

The following simple reproducer can cause the issue described above:

int main(void)
{
int sock;
struct sockaddr_vm addr = {
.svm_family = AF_VSOCK,
.svm_cid = VMADDR_CID_ANY,
.svm_port = 1234,
};

sock = socket(AF_VSOCK, SOCK_STREAM, 0);
connect(sock, (struct sockaddr *)&addr, sizeof(addr));
return 0;
}

This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the
`struct virtio_vsock_hdr` are not initialized when a new skb is allocated
in `virtio_transport_init_hdr()`. This patch resolves the issue by
initializing these fields during allocation.

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: virtio/vsock: corrige el valor uninit en virtio_transport_recv_pkt(). KMSAN informó el siguiente problema de acceso al valor uninit: ================ ===================================== ERROR: KMSAN: valor uninit en virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 Process_one_work workqueue.c:2630 [en línea] process_scheduled_works+ 0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit se almacenó en la memoria en: virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [en línea] virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virt io_transport_common.c:1415 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 Process_one_work kernel/workqueue.c:2630 [en línea] Process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 trabajador_thread+0xeca/0x14d0 kernel/workqueue.c:2784 hilo +0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit se creó en: slab_post_alloc_hook+ 0x105/0xad0 mm/slab.h: 767 slab_alloc_node mm/slub.c: 3478 [inline] kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c: 3523 kmalloc_reserve+0x13c/0x4a0 net/skbuff. fd /0x770 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [en línea] virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [en línea] virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c: 58 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [en línea] virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/v sock_loopback.c:120 proceso_one_work kernel/workqueue.c:2630 [en línea] Process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 trabajador_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/ Process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 CPU: 1 PID: 10664 Comm: kworker/1:5 No contaminado 6.6.0-rc3-00146-g9f3ebbef746f #3 Nombre de hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 01/04/2014 Cola de trabajo: vsock-loopback vsock_loopback_work ===================== ================================= El siguiente reproductor simple puede causar el problema descrito anteriormente: int main(void) { calcetín interno; struct sockaddr_vm addr = { .svm_family = AF_VSOCK, .svm_cid = VMADDR_CID_ANY, .svm_port = 1234, }; sock = socket(AF_VSOCK, SOCK_STREAM, 0); connect(socket, (struct sockaddr *)&addr, sizeof(addr)); return 0; } Este problema ocurre porque los campos `buf_alloc` y `fwd_cnt` de `struct virtio_vsock_hdr` no se inicializan cuando se asigna un nuevo skb en `virtio_transport_init_hdr()`. Este parche resuelve el problema inicializando estos campos durante la asignación.

*Credits: N/A
CVSS Scores
Attack Vector
-
Attack Complexity
-
Privileges Required
-
User Interaction
-
Scope
-
Confidentiality
-
Integrity
-
Availability
-
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-21 CVE Reserved
  • 2024-05-21 CVE Published
  • 2024-05-22 EPSS Updated
  • 2024-08-02 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 6.3 < 6.6.2
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.3 < 6.6.2"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 6.3 < 6.7
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.3 < 6.7"
en
Affected