From dde3929e8d901ae9a7c29d0577ce9ca5cb4db35d Mon Sep 17 00:00:00 2001 From: =?utf8?q?Pali=20Roh=C3=A1r?= Date: Tue, 7 Jul 2026 11:03:18 +0200 Subject: [PATCH] cifs: Fix support for creating SFU socket MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit SFU sockets are natively supported by Interix 3.0 subsystem and also by later versions. It is part of Microsoft SFU (Windows Services for UNIX) and Microsoft SUA (Subsystem for UNIX-based Applications). They can be created and existing (stored on local disk or remote SMB share) can be recognized. SFU sockets are recognized also by NFS server included in Windows Server. Windows NFS server versions since Windows Server 2012 uses new reparse point format for storing new sockets, but still can recognize this old format (also in the latest Windows Server 2022 version). SFU-style socket is a regular file which has system attribute set and content of the file is one zero byte. These SFU-style sockets are already recognized by Linux SMB client. But Linux SMB client is currently creating new SFU socket in different format which is not compatible with all those SFU applications. Fix this by creating new sockets in correct SFU format which would be recognized by all SFU, SUA, NFS and existing Linux SMB clients. This change affects only creating new sockets when mount option -o sfu is used. Signed-off-by: Pali Rohár Acked-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French --- fs/smb/client/smb2ops.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 06e9322a762a..b4fa43f32e51 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -5286,10 +5286,9 @@ int __cifs_sfu_make_node(unsigned int xid, struct inode *inode, data = (u8 *)symname_utf16; break; case S_IFSOCK: - type_len = 8; - strscpy(type, "LnxSOCK"); - data = (u8 *)&pdev; - data_len = sizeof(pdev); + /* SFU socket is system file with one zero byte */ + type_len = 1; + type[0] = '\0'; break; case S_IFIFO: type_len = 8; -- 2.47.3