8.1Alta

CVE-2026-98454smb: client: fix create context out-of-bounds reads

Linux Linux Publicada: (hace 28 días)

Descripción

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix create context out-of-bounds reads smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId. The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted. Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

FabricanteProductoVersiones
Linux Linux 3.7
linux linux kernel 3.7 – < 6.6.158

Correcciones de Ubuntu

  • USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities Ubuntu 24.04 · 13.11.2026 · linux-nvidia-tegra
  • USN-9066-1 Linux kernel (HWE) vulnerabilities Ubuntu 22.04 · 12.11.2026 · linux-hwe-6.8
  • USN-8959-1 Linux kernel vulnerabilities Ubuntu 26.04, 24.04 · 03.11.2026 · linux, linux-aws, linux-gcp, linux-hwe-7.0, linux-ibm, linux-oracle
  • USN-8960-1 Linux kernel (OEM) vulnerabilities Ubuntu 26.04 · 03.11.2026 · linux-oem-7.0

Referencias y parches