# CVE-2026-46207: vsock/virtio: fix empty payload in tap skb for non-linear buffers

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-05-28 · Updated: 2026-06-14

## Affected

- Linux: version range not reported
- Linux: 6.7

## Description

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix empty payload in tap skb for non-linear buffers For non-linear skbs, virtio_transport_build_skb() goes through virtio_transport_copy_nonlinear_skb() to copy the original payload in the new skb to be delivered to the vsockmon tap device. This manually initializes an iov_iter but does not set iov_iter.count. Since the iov_iter is zero-initialized, the copy length is zero and no payload is actually copied to the monitor interface, leaving data un-initialized. Fix this by removing the linear vs non-linear split and using skb_copy_datagram_iter() with iov_iter_kvec() for all cases, as vhost-vsock already does. This handles both linear and non-linear skbs, properly initializes the iov_iter, and removes the now unused virtio_transport_copy_nonlinear_skb(). While touching this code, let's also check the return value of skb_copy_datagram_iter(), even though it's unlikely to fail.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/06747f52ab157591cec7e5623a759473b66ef6f6
- https://git.kernel.org/stable/c/52da6a74ca3de0fcda60301096b71534b3b18641
- https://git.kernel.org/stable/c/378b131a25bd1a5ee27ca199fe486c299d5350c5
- https://git.kernel.org/stable/c/3a3e3d90cbc79600544536723911657730759af3

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Page: https://cve.now/CVE-2026-46207
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