Bug 2507076 (CVE-2026-64391) - CVE-2026-64391 kernel: ksmbd: use opener credentials for ADS I/O
Summary: CVE-2026-64391 kernel: ksmbd: use opener credentials for ADS I/O
Keywords:
Status: NEW
Alias: CVE-2026-64391
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 10:03 UTC by OSIDB Bzimport
Modified: 2026-07-29 17:25 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-07-25 10:03:43 UTC
In the Linux kernel, the following vulnerability has been resolved:

ksmbd: use opener credentials for ADS I/O

Alternate data streams are stored as xattrs. Unlike regular file I/O,
their read and write paths therefore call VFS xattr helpers which recheck
inode permissions and LSM policy using the current task credentials.

Run ADS I/O with the credentials captured when the SMB handle was opened.

Comment 1 Mauro Matteo Cascella 2026-07-29 17:15:58 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072527-CVE-2026-64391-ae65@gregkh/T


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