From 11e31647c9263185cfd990db656dbb7f06697faf Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Mon, 8 Feb 2016 13:44:01 +0530 Subject: [PATCH] cifs: remove any preceding delimiter from prefix_path We currently do not check if any delimiter exists before the prefix path in cifs_compose_mount_options(). Consequently when building the devname using cifs_build_devname() we can end up with multiple delimiters separating the UNC and the prefix path. An issue was reported by the customer mounting a folder within a DFS share from a Netapp server which uses McAfee antivirus. We have narrowed down the cause to the use of double backslashes in the file name used to open the file. This was determined to be caused because of additional delimiters as a result of the bug. In addition to changes in cifs_build_devname(), we also fix cifs_parse_devname() to ignore any preceding delimiter for the prefix path. The problem was originally reported on RHEL 6 in RHEL bz 1252721. This is the upstream version of the fix. The fix was confirmed by looking at the packet capture of a DFS mount. Signed-off-by: Sachin Prabhu Signed-off-by: Steve French --- fs/cifs/cifs_dfs_ref.c | 6 +++++- fs/cifs/connect.c | 8 ++++++-- 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c index 94f2c8a9ae6d..ec9dbbcca3b9 100644 --- a/fs/cifs/cifs_dfs_ref.c +++ b/fs/cifs/cifs_dfs_ref.c @@ -151,8 +151,12 @@ char *cifs_compose_mount_options(const char *sb_mountdata, if (sb_mountdata == NULL) return ERR_PTR(-EINVAL); - if (strlen(fullpath) - ref->path_consumed) + if (strlen(fullpath) - ref->path_consumed) { prepath = fullpath + ref->path_consumed; + /* skip initial delimiter */ + if (*prepath == '/' || *prepath == '\\') + prepath++; + } *devname = cifs_build_devname(ref->node_name, prepath); if (IS_ERR(*devname)) { diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 6f62ac821a84..078b7311c3fa 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1196,8 +1196,12 @@ cifs_parse_devname(const char *devname, struct smb_vol *vol) convert_delimiter(vol->UNC, '\\'); - /* If pos is NULL, or is a bogus trailing delimiter then no prepath */ - if (!*pos++ || !*pos) + /* skip any delimiter */ + if (*pos == '/' || *pos == '\\') + pos++; + + /* If pos is NULL then no prepath */ + if (!*pos) return 0; vol->prepath = kstrdup(pos, GFP_KERNEL); -- 2.20.1