CVE-2026-64399
CRITICAL
9,8
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Description
AI Translation Available
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE
The FSCTL_DUPLICATE_EXTENTS_TO_FILE arm of smb2_ioctl() overwrites the
destination file's data via vfs_clone_file_range() with neither the
share-level KSMBD_TREE_CONN_FLAG_WRITABLE check nor a per-handle
fp->daccess check that the other write-bearing arms carry. A client can
overwrite destination data on a read-only share, or from a handle opened
with only FILE_WRITE_ATTRIBUTES (which still yields an FMODE_WRITE filp).
FILE_WRITE_ATTRIBUTES-only destination handle overwrote the file's data via
the clone. Add both checks, matching the FSCTL_SET_SPARSE permission fix;
require FILE_WRITE_DATA since this writes data.
https://git.kernel.org/stable/c/388e4139db27a9e3612c9d356b826f5b1ff6a9e3
https://git.kernel.org/stable/c/620d133d469295ee7c017ca6aafac335f65c4a5a
https://git.kernel.org/stable/c/9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6
https://git.kernel.org/stable/c/baae7b39673ec21073a25e3d14f8feaada01d5df
https://git.kernel.org/stable/c/bf460ad5958d506492de4524a656439da3f99c51
https://git.kernel.org/stable/c/c917e4522d251071dde9871b9142d8ea1186ebfe