From 374402a2a1dfbbee8ab1a5a32ec4887bf8c15d52 Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Thu, 15 Dec 2016 12:31:19 +0530 Subject: [PATCH] cifs_get_root shouldn't use path with tree name When a server returns the optional flag SMB_SHARE_IS_IN_DFS in response to a tree connect, cifs_build_path_to_root() will return a pathname which includes the hostname. This causes problems with cifs_get_root() which separates each component and does a lookup for each component of the path which in this case will incorrectly include looking up the hostname component as a path component. We encountered a problem with dfs shares hosted by a Netapp. When connecting to nodes pointed to by the DFS share. The tree connect for these nodes return SMB_SHARE_IS_IN_DFS resulting failures in lookup in cifs_get_root(). RH bz: 1373153 The patch was tested against a Netapp simulator and by a user using an actual Netapp server. Signed-off-by: Sachin Prabhu Reported-by: Pierguido Lambri Reviewed-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifsfs.c | 2 +- fs/cifs/cifsproto.h | 3 ++- fs/cifs/connect.c | 3 ++- fs/cifs/dir.c | 4 ++-- 4 files changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 15261ba464c5..f135f088cdff 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -615,7 +615,7 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb) return dget(sb->s_root); full_path = cifs_build_path_to_root(vol, cifs_sb, - cifs_sb_master_tcon(cifs_sb)); + cifs_sb_master_tcon(cifs_sb), 0); if (full_path == NULL) return ERR_PTR(-ENOMEM); diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index cd8025a249bb..c7b3c841e660 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -63,7 +63,8 @@ extern void exit_cifs_spnego(void); extern char *build_path_from_dentry(struct dentry *); extern char *cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, - struct cifs_tcon *tcon); + struct cifs_tcon *tcon, + int add_treename); extern char *build_wildcard_path_from_dentry(struct dentry *direntry); extern char *cifs_compose_mount_options(const char *sb_mountdata, const char *fullpath, const struct dfs_info3_param *ref, diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 1847aa8390ff..851256e99cf0 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3765,7 +3765,8 @@ remote_path_check: /* * cifs_build_path_to_root works only when we have a valid tcon */ - full_path = cifs_build_path_to_root(volume_info, cifs_sb, tcon); + full_path = cifs_build_path_to_root(volume_info, cifs_sb, tcon, + tcon->Flags & SMB_SHARE_IS_IN_DFS); if (full_path == NULL) { rc = -ENOMEM; goto mount_fail_check; diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 789ff1df2d8d..2c227a99f369 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -47,7 +47,7 @@ renew_parental_timestamps(struct dentry *direntry) char * cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, - struct cifs_tcon *tcon) + struct cifs_tcon *tcon, int add_treename) { int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0; int dfsplen; @@ -59,7 +59,7 @@ cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, return full_path; } - if (tcon->Flags & SMB_SHARE_IS_IN_DFS) + if (add_treename) dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1); else dfsplen = 0;