CVE-2026-99083
kernel: ksmbd: fix heap out-of-bounds write in krb5_authenticate()
Sévérité par source
Le label propre à Trivy est CRITICAL. Critique selon Red Hat.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix heap out-of-bounds write in krb5_authenticate() In krb5_authenticate(), out_len is calculated to determine available headroom in response_buf for the incoming Kerberos AP-REP token. However, when SMB2_SESSION_SETUP is processed as a non-first element of a compounded SMB2 request, the calculation omits work->next_smb2_rsp_hdr_off. This causes out_len to overstate remaining buffer headroom by the cumulative size of prior responses in the compound chain. Consequently, the length check in ksmbd_krb5_authenticate() (*out_len <= resp->spnego_blob_len) passes erroneously, allowing memcpy() to write the AP-REP blob past the end of response_buf into adjacent kernel heap memory. Fix this by subtracting work->next_smb2_rsp_hdr_off when computing out_len, ensuring it accurately reflects physical remaining buffer space.
Paquets affectés et versions corrigées
| Source | Paquet | Corrigé en |
|---|---|---|
| debian 11 | linux | pas de correctif indiqué |
| debian 12 | linux | pas de correctif indiqué |
| debian 13 | linux | pas de correctif indiqué |
| debian 14 | linux | 7.2.12-1 |
| echo | linux | 1 |
Références
- https://access.redhat.com/security/cve/CVE-2026-99083
- https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-99083.mbox
- https://git.kernel.org/stable/c/23a0be6a84a38ac169eeab49017934e8e27c65f0
- https://git.kernel.org/stable/c/4722d06b2907585074252061b1024a696c1cfc23
- https://git.kernel.org/stable/c/517404e157395d0f8da125ca956c566895dfcd06
- https://git.kernel.org/stable/c/59c6dcc5dd9dafe764ca0d40525933b2be69b059
- https://git.kernel.org/stable/c/80af1bde97d5a85ad6f2c40ca894ccc8fa75a27a
- https://nvd.nist.gov/vuln/detail/CVE-2026-99083