usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb() (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.13 % · percentile 3 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb() The block_len read from the host-supplied NTB header is checked against ntb_max but has no lower bound. When block_len is smaller than opts->ndp_size, the bounds check of: ndp_index > (block_len - opts->ndp_size) will underflow producing a huge unsigned value that ndp_index can never exceed, defeating the check entirely. The same underflow occurs in the datagram index checks against block_len - opts->dpe_size. With those checks neutered, a malicious USB host can choose ndp_index and datagram offsets that point past the actual transfer, and the skb_put_data() copies adjacent kernel memory into the network skb. Fix this by rejecting block lengths that cannot hold at least the NTB header plus one NDP. This will make block_len - opts->ndp_size and block_len - opts->dpe_size both well-defined. Commit 8d2b1a1ec9f5 ("CDC-NCM: avoid overflow in sanity checking") fixed a related class of issues on the host side of NCM.
Weaknesses (CWE)
- CWE-191 — Integer Underflow (Wrap or Wraparound)
References
- https://git.kernel.org/stable/c/068a7f2749fff6462a0a908ec415b885fe430f50
- https://git.kernel.org/stable/c/1425655c2870054c3ab4712e2b6dbdd331597ada
- https://git.kernel.org/stable/c/8b3b7bd3c02f98634baaf36c7fc7ac915f6517ca
- https://git.kernel.org/stable/c/0f156bb5334e588034ca68ac2ee92b23f66e56e7
- https://git.kernel.org/stable/c/8757a2593631443648218244b9788e193ae0fdc1
- https://git.kernel.org/stable/c/6762f8a95772265dd0c2ffe7f400493f3115b135
- https://git.kernel.org/stable/c/d58ba8f6546232f8414f396c189297dbee03f1a7
- https://git.kernel.org/stable/c/74908b0318d1df1188457040b8714ff4d4b68126
- https://git.kernel.org/stable/c/8f993d30b95dc9557a8a96ceca11abed674c8acb
- https://access.redhat.com/security/cve/CVE-2026-31617
- https://bugzilla.redhat.com/show_bug.cgi?id=2461448
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31617.json
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
European references
- ENISA EUVD · EUVD-2026-25510
- GCVE · GCVE-0-2026-31617
CERT-FR advisories
- CERTFR-2026-AVI-1298 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1229 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1093 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1064 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0985 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0927 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0862 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0861 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0831 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0548 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.9 < 6.6.136cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.12 < 6.12.83cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.24cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 6.19.14cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 7.0 < 7.0.1
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52 < 068a7f2749fff6462a0a908ec415b885fe430f50 ; affected 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52 < 1425655c2870054c3ab4712e2b6dbdd331597ada ; affected 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52 < 8b3b7bd3c02f98634baaf36c7fc7ac915f6517ca ; affected 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52 < 0f156bb5334e588034ca68ac2ee92b23f66e56e7 ; affected 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52 < 8757a2593631443648218244b9788e193ae0fdc1 ; affected 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52 < 6762f8a95772265dd0c2ffe7f400493f3115b135 |
| Linux · Linux | affected 5.9 ; unaffected 0 < 5.9 ; unaffected 5.10.258 ≤ 5.10.* ; unaffected 5.15.209 ≤ 5.15.* ; unaffected 6.1.175 ≤ 6.1.* ; unaffected 6.6.136 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |