CVE-2026-64395 PUBLISHED

ksmbd: require source read access for duplicate extents

Assigner: Linux
Reserved: 19.07.2026 Published: 25.07.2026 Updated: 25.07.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 2d2ab6983620c2d60ce7db72133984ca3873b929 (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 67bdad9cf01b25030e3bf00bbce6c309319d6663 (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to db231af842868268839f9f9619c68cb27830d8be (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to a10942af27832c2761d020863a46e79bebe0567d (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to cedff600f1642aa982178503552f0d007bc829c8 (excl.)
  • affected from 0 to 6.1.178 (excl.)
  • affected from 0 to 6.6.145 (excl.)
  • affected from 0 to 6.12.96 (excl.)
  • affected from 0 to 6.18.39 (excl.)
  • affected from 0 to 7.1.4 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • unaffected from 6.1.178 to 6.1.* (incl.)
  • unaffected from 6.6.145 to 6.6.* (incl.)
  • unaffected from 6.12.96 to 6.12.* (incl.)
  • unaffected from 6.18.39 to 6.18.* (incl.)
  • unaffected from 7.1.4 to 7.1.* (incl.)
  • unaffected from 7.2-rc1 to * (incl.)

References