CVE-2026-64395

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate extents FSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to vfs_clone_file_range() or vfs_copy_file_range() without checking the SMB access mask granted to the source handle. A handle opened with attribute access can consequently be used to copy file contents into an attacker-readable destination. Require FILE_READ_DATA on the source handle before either VFS operation, matching other ksmbd data-copy paths.

References

• https://git.kernel.org/stable/c/2d2ab6983620c2d60ce7db72133984ca3873b929
• https://git.kernel.org/stable/c/67bdad9cf01b25030e3bf00bbce6c309319d6663
• https://git.kernel.org/stable/c/a10942af27832c2761d020863a46e79bebe0567d
• https://git.kernel.org/stable/c/b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f
• https://git.kernel.org/stable/c/cedff600f1642aa982178503552f0d007bc829c8
• https://git.kernel.org/stable/c/db231af842868268839f9f9619c68cb27830d8be