UBUNTU-CVE-2026-46207
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.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
4 explicit affected versions
50 explicit affected versions
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12 explicit affected versions
19 explicit affected versions
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6 explicit affected versions
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2 explicit affected versions
10 explicit affected versions
37 explicit affected versions
26 explicit affected versions
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13 explicit affected versions
44 explicit affected versions
35 explicit affected versions
1 explicit affected versions
18 explicit affected versions
1 explicit affected versions
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13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
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1 explicit affected versions
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10 explicit affected versions
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7 explicit affected versions
48 explicit affected versions
8 explicit affected versions
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11 explicit affected versions
7 explicit affected versions
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1 explicit affected versions
7 explicit affected versions
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12 explicit affected versions
10 explicit affected versions
12 explicit affected versions
41 explicit affected versions
9 explicit affected versions
9 explicit affected versions
16 explicit affected versions
6 explicit affected versions
17 explicit affected versions
27 explicit affected versions
34 explicit affected versions
10 explicit affected versions
37 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
39 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
26 explicit affected versions
10 explicit affected versions
13 explicit affected versions
29 explicit affected versions
13 explicit affected versions
12 explicit affected versions
41 explicit affected versions
40 explicit affected versions
8 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
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19 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
11 explicit affected versions
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12 explicit affected versions
10 explicit affected versions
16 explicit affected versions
17 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
39 explicit affected versions
35 explicit affected versions
48 explicit affected versions
11 explicit affected versions
10 explicit affected versions
13 explicit affected versions
46 explicit affected versions
16 explicit affected versions
50 explicit affected versions
10 explicit affected versions
3 explicit affected versions
7 explicit affected versions
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51 explicit affected versions
16 explicit affected versions
18 explicit affected versions
43 explicit affected versions
12 explicit affected versions
7 explicit affected versions
27 explicit affected versions
3 explicit affected versions
8 explicit affected versions
43 explicit affected versions
8 explicit affected versions
3 explicit affected versions
5 explicit affected versions
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6 explicit affected versions
10 explicit affected versions
7 explicit affected versions
46 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
50 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
17 explicit affected versions
11 explicit affected versions
39 explicit affected versions
18 explicit affected versions
14 explicit affected versions
6 explicit affected versions
7 explicit affected versions
4 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
13 explicit affected versions
43 explicit affected versions
16 explicit affected versions
10 explicit affected versions
8 explicit affected versions
45 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
14 explicit affected versions
11 explicit affected versions
1 explicit affected versions
19 explicit affected versions
6 explicit affected versions
39 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/3a3e3d90cbc79600544536723911657730759af3
- https://git.kernel.org/stable/c/06747f52ab157591cec7e5623a759473b66ef6f6
- https://git.kernel.org/stable/c/378b131a25bd1a5ee27ca199fe486c299d5350c5
- https://git.kernel.org/stable/c/3a3e3d90cbc79600544536723911657730759af3
- https://git.kernel.org/stable/c/52da6a74ca3de0fcda60301096b71534b3b18641
- https://ubuntu.com/security/CVE-2026-46207
- https://ubuntu.com/security/notices/USN-8566-1
- https://ubuntu.com/security/notices/USN-8567-1
- https://ubuntu.com/security/notices/USN-8568-1
- https://ubuntu.com/security/notices/USN-8569-1
- https://ubuntu.com/security/notices/USN-8574-1
- https://ubuntu.com/security/notices/USN-8574-2
- https://ubuntu.com/security/notices/USN-8574-3
- https://ubuntu.com/security/notices/USN-8593-1
- https://ubuntu.com/security/notices/USN-8595-1
- https://ubuntu.com/security/notices/USN-8595-2
- https://ubuntu.com/security/notices/USN-8595-3
- https://ubuntu.com/security/notices/USN-8596-1
- https://ubuntu.com/security/notices/USN-8603-1
- https://ubuntu.com/security/notices/USN-8606-1
- https://ubuntu.com/security/notices/USN-8607-1
- https://ubuntu.com/security/notices/USN-8608-1
- https://ubuntu.com/security/notices/USN-8609-1
- https://ubuntu.com/security/notices/USN-8618-1
- https://ubuntu.com/security/notices/USN-8619-1
- https://www.cve.org/CVERecord?id=CVE-2026-46207