CVEvulnerability
CVE-2026-98454
8.1 HIGH
Official page ↗
- Status
- Received
- Published
- 2026-10-18
- Last modified
- 2026-10-24
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 8.1 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Description
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.
References
- https://git.kernel.org/stable/c/05a7fd80024ff32b9b40ab1478bb172eeab1c386 git.kernel.org
- https://git.kernel.org/stable/c/28bc9a871799363afa3139e961a8e3684feb8704 git.kernel.org
- https://git.kernel.org/stable/c/67f4c1c6a1b51e203d986779299824d1c2c590a6 git.kernel.org
- https://git.kernel.org/stable/c/cecc5399987e73a528ce2b662eeb54af69163cbd git.kernel.org
- https://git.kernel.org/stable/c/e4c49012708c917eafd9c27054b02d0f8b30fe64 git.kernel.org