CVE-2022-50271 vhost/vsock: Use kvmalloc/kvfree for larger packets.
A flaw in the Linux kernel vhost/vsock module causes memory allocation failures when handling large packets, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50271?
CVE-2022-50271 is a medium-severity denial of service vulnerability in Linux kernel, published on 15 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
vhost/vsock: Use kvmalloc/kvfree for larger packets.
When copying a large file over sftp over vsock, data size is usually 32kB, and kmalloc seems to fail to try to allocate 32 32kB regions.
vhost-5837: page allocation failure: order:4, mode:0x24040c0 Call Trace: [<ffffffffb6a0df64>] dump_stack+0x97/0xdb [<ffffffffb68d6aed>] warn_alloc_failed+0x10f/0x138 [<ffffffffb68d868a>] ? __alloc_pages_direct_compact+0x38/0xc8 [<ffffffffb664619f>] __alloc_pages_nodemask+0x84c/0x90d [<ffffffffb6646e56>] alloc_kmem_pages+0x17/0x19 [<ffffffffb6653a26>] kmalloc_order_trace+0x2b/0xdb [<ffffffffb66682f3>] __kmalloc+0x177/0x1f7 [<ffffffffb66e0d94>] ? copy_from_iter+0x8d/0x31d [<ffffffffc0689ab7>] vhost_vsock_handle_tx_kick+0x1fa/0x301 [vhost_vsock] [<ffffffffc06828d9>] vhost_worker+0xf7/0x157 [vhost] [<ffffffffb683ddce>] kthread+0xfd/0x105 [<ffffffffc06827e2>] ? vhost_dev_set_owner+0x22e/0x22e [vhost] [<ffffffffb683dcd1>] ? flush_kthread_worker+0xf3/0xf3 [<ffffffffb6eb332e>] ret_from_fork+0x4e/0x80 [<ffffffffb683dcd1>] ? flush_kthread_worker+0xf3/0xf3
Work around by doing kvmalloc instead.
Which versions are affected by CVE-2022-50271?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50271?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-50271 being exploited?
There is no known exploitation of CVE-2022-50271 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50271, GHSA-7qgr-rfmm-pgc2, UBUNTU-CVE-2022-50271.