smb: client: fix off-by-8 bounds check in check_wsl_eas() (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.13 % · percentile 2 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Analyzed
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix off-by-8 bounds check in check_wsl_eas() The bounds check uses (u8 *)ea + nlen + 1 + vlen as the end of the EA name and value, but ea_data sits at offset sizeof(struct smb2_file_full_ea_info) = 8 from ea, not at offset 0. The strncmp() later reads ea->ea_data[0..nlen-1] and the value bytes follow at ea_data[nlen+1..nlen+vlen], so the actual end is ea->ea_data + nlen + 1 + vlen. Isn't pointer math fun? The earlier check (u8 *)ea > end - sizeof(*ea) only guarantees the 8-byte header is in bounds, but since the last EA is placed within 8 bytes of the end of the response, the name and value bytes are read past the end of iov. Fix this mess all up by using ea->ea_data as the base for the bounds check. An "untrusted" server can use this to leak up to 8 bytes of kernel heap into the EA name comparison and influence which WSL xattr the data is interpreted as.
Weaknesses (CWE)
- CWE-125 — Out-of-bounds Read
References
- https://git.kernel.org/stable/c/bfbc74df8bbe095b3ed68f6d4487b368af087890
- https://git.kernel.org/stable/c/5cc0574c84aa73946ade587c41e81757b8b01cb5
- https://git.kernel.org/stable/c/b2b76d09a64c538c57006180103fc1841e8cfa66
- https://git.kernel.org/stable/c/ba3ad159aa61810bbe0acaf39578b1ebfb6f1a18
- https://git.kernel.org/stable/c/a893f1757d9a4009e4a8d7ceb2312142fe29cea4
- https://git.kernel.org/stable/c/3d8b9d06bd3ac4c6846f5498800b0f5f8062e53b
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-25507
- GCVE · GCVE-0-2026-31614
CERT-FR advisories
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0864 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0861 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0833 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0831 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0807 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0782 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0745 — Multiples vulnérabilités dans le noyau Linux de SUSE · 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:*:*:*:*:*:*:*:*≥ 6.6.32 < 6.6.136cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.9 < 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 7449d736bbbd160c76b01b8fcdf72f58a8757d4b < bfbc74df8bbe095b3ed68f6d4487b368af087890 ; affected ea41367b2a602f602ea6594fc4a310520dcc64f4 < 5cc0574c84aa73946ade587c41e81757b8b01cb5 ; affected ea41367b2a602f602ea6594fc4a310520dcc64f4 < b2b76d09a64c538c57006180103fc1841e8cfa66 ; affected ea41367b2a602f602ea6594fc4a310520dcc64f4 < ba3ad159aa61810bbe0acaf39578b1ebfb6f1a18 ; affected ea41367b2a602f602ea6594fc4a310520dcc64f4 < a893f1757d9a4009e4a8d7ceb2312142fe29cea4 ; affected ea41367b2a602f602ea6594fc4a310520dcc64f4 < 3d8b9d06bd3ac4c6846f5498800b0f5f8062e53b |
| Linux · Linux | affected 6.9 ; unaffected 0 < 6.9 ; unaffected 6.6.136 ≤ 6.6.* ; unaffected 6.12.83 ≤ 6.12.* ; unaffected 6.18.24 ≤ 6.18.* ; unaffected 6.19.14 ≤ 6.19.* |
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 |