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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 31 Dec 2024 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-908
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'}


Thu, 19 Dec 2024 09:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T07:44:08.475Z

Reserved: 2024-05-21T15:19:24.254Z

Link: CVE-2023-52842

cve-icon Vulnrichment

Updated: 2024-08-02T23:11:36.053Z

cve-icon NVD

Status : Analyzed

Published: 2024-05-21T16:15:21.510

Modified: 2024-12-31T19:50:07.140

Link: CVE-2023-52842

cve-icon Redhat

Severity : Low

Publid Date: 2024-05-21T00:00:00Z

Links: CVE-2023-52842 - Bugzilla

cve-icon OpenCVE Enrichment

No data.