CVE-2026-99114

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

ksmbd: initialize FileSystemControlFlags in FS CONTROL INFORMATION

smb2 get info filesystem() reports 48 bytes for FS CONTROL INFORMATION, that is the whole of struct smb2 fs control info, but never assigns FileSystemControlFlags. Those four bytes go to the client as they are found in the response buffer.

The buffer is zeroed on allocation, so a standalone request leaks nothing. A compound request can leak: the offset of the next response is advanced by the length pinned for the previous one, so a reply that was written into the buffer and then dropped in favour of the short error response of smb2 set err rsp() stays there, and the next reply is laid over it with only the header cleared.

ksmbd does not implement quota tracking, so report no control flags.