From e183785f2529b4135f00a0330a3b08e7c86530c8 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Thu, 27 Aug 2020 11:20:19 -0300 Subject: [PATCH] cifs: fix check of tcon dfs in smb1 For SMB1, the DFS flag should be checked against tcon->Flags rather than tcon->share_flags. While at it, add an is_tcon_dfs() helper to check for DFS capability in a more generic way. Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French Reviewed-by: Shyam Prasad N --- fs/cifs/cifsglob.h | 15 +++++++++++++++ fs/cifs/connect.c | 2 +- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index b296964b8afa..b565d83ba89e 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -2031,4 +2031,19 @@ static inline bool is_smb1_server(struct TCP_Server_Info *server) return strcmp(server->vals->version_string, SMB1_VERSION_STRING) == 0; } +static inline bool is_tcon_dfs(struct cifs_tcon *tcon) +{ + /* + * For SMB1, see MS-CIFS 2.4.55 SMB_COM_TREE_CONNECT_ANDX (0x75) and MS-CIFS 3.3.4.4 DFS + * Subsystem Notifies That a Share Is a DFS Share. + * + * For SMB2+, see MS-SMB2 2.2.10 SMB2 TREE_CONNECT Response and MS-SMB2 3.3.4.14 Server + * Application Updates a Share. + */ + if (!tcon || !tcon->ses || !tcon->ses->server) + return false; + return is_smb1_server(tcon->ses->server) ? tcon->Flags & SMB_SHARE_IS_IN_DFS : + tcon->share_flags & (SHI1005_FLAGS_DFS | SHI1005_FLAGS_DFS_ROOT); +} + #endif /* _CIFS_GLOB_H */ diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index a275ee399dce..392c44d64d8a 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -4909,7 +4909,7 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) if (!tcon) continue; /* Make sure that requests go through new root servers */ - if (tcon->share_flags & (SHI1005_FLAGS_DFS | SHI1005_FLAGS_DFS_ROOT)) { + if (is_tcon_dfs(tcon)) { put_root_ses(root_ses); set_root_ses(cifs_sb, ses, &root_ses); }