CVE-2026-46207

Summary

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.

Impact & exploitability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/06747f52ab157591cec7e5623a759473b66ef6f6 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/06747f52ab157591cec7e5623a759473b66ef6f6Patch
• https://git.kernel.org/stable/c/378b131a25bd1a5ee27ca199fe486c299d5350c5Patch
• https://git.kernel.org/stable/c/3a3e3d90cbc79600544536723911657730759af3Patch
• https://git.kernel.org/stable/c/52da6a74ca3de0fcda60301096b71534b3b18641Patch