Description
In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb()

When unpacking host-supplied NTBs, ncm_unwrap_ntb() checks datagram length
against frame_max but does not verify that the datagram fits within the
declared block length. Additionally, when decoding multiple NTBs from a
single socket buffer, subsequent block lengths are not checked against the
actual remaining buffer data.

With these checks missing, a malicious USB host can specify datagram
offsets and lengths that point beyond the block, or supply secondary NTB
headers declaring lengths larger than the buffer. skb_put_data() then
copies adjacent kernel memory from skb_shared_info into the network skb.

Fix this by verifying that sufficient buffer space remains for the NTB
header before parsing, handling zero-length block declarations, ensuring
that block lengths never exceed the remaining buffer space, and verifying
that each datagram payload stays strictly within the block boundary.
Published: 2026-08-10
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Mon, 10 Aug 2026 12:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb() When unpacking host-supplied NTBs, ncm_unwrap_ntb() checks datagram length against frame_max but does not verify that the datagram fits within the declared block length. Additionally, when decoding multiple NTBs from a single socket buffer, subsequent block lengths are not checked against the actual remaining buffer data. With these checks missing, a malicious USB host can specify datagram offsets and lengths that point beyond the block, or supply secondary NTB headers declaring lengths larger than the buffer. skb_put_data() then copies adjacent kernel memory from skb_shared_info into the network skb. Fix this by verifying that sufficient buffer space remains for the NTB header before parsing, handling zero-length block declarations, ensuring that block lengths never exceed the remaining buffer space, and verifying that each datagram payload stays strictly within the block boundary.
Title usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-10T12:03:45.579Z

Reserved: 2026-07-30T09:28:09.386Z

Link: CVE-2026-68368

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.