Bug 2507166 (CVE-2026-64257) - CVE-2026-64257 kernel: smb: client: reject overlapping data areas in SMB2 responses
Summary: CVE-2026-64257 kernel: smb: client: reject overlapping data areas in SMB2 res...
Keywords:
Status: NEW
Alias: CVE-2026-64257
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-25 10:08 UTC by OSIDB Bzimport
Modified: 2026-07-29 13:07 UTC (History)
2 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-07-25 10:08:33 UTC
In the Linux kernel, the following vulnerability has been resolved:

smb: client: reject overlapping data areas in SMB2 responses

Commit 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to
responses without data area") restricted the implied bcc[0] length
exception to responses without a data area. However, the overlap
handling in __smb2_calc_size() clears data_length, which can make an
invalid response appear to have no data area and so qualify for the
exception.

Track data area overlap separately and reject such responses before
applying the length compatibility exceptions.


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