CVE-2026-68457

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: use opener credentials for FSCTL mutations

SETSPARSE, SETZERODATA and SETCOMPRESSION operate on an open SMB

handle but call VFS xattr, fallocate or fileattr helpers with the current

ksmbd worker credentials. Those helpers can revalidate inode permissions,

ownership and LSM policy independently of the SMB handle access mask.

Run each operation with the credentials captured in the target file when

the handle was opened. Keep credential handling local to these single-file

FSCTLs rather than applying session credentials to the complete IOCTL

handler, which also contains handle-less and multi-handle operations.