cifs: fix up handling of prefixpath= option

Currently the code takes care to ensure that the prefixpath has a
leading '/' delimiter. What if someone passes us a prefixpath with a
leading '\\' instead? The code doesn't properly handle that currently
AFAICS.

Let's just change the code to skip over any leading delimiter character
when copying the prepath. Then, fix up the users of the prepath option
to prefix it with the correct delimiter when they use it.

Also, there's no need to limit the length of the prefixpath to 1k. If
the server can handle it, why bother forbidding it?

Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 9c5c8b8c19fe88042fe40d6d1b6273682c10efad..94c4484c9ea36a62b4ff7419205117b0c61606b6 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1612,31 +1612,14 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                        }
                        break;
                case Opt_prefixpath:
-                       string = match_strdup(args);
-                       if (string == NULL)
-                               goto out_nomem;
-
-                       temp_len = strnlen(string, 1024);
-                       if (string[0] != '/')
-                               temp_len++; /* missing leading slash */
-                       if (temp_len > 1024) {
-                               printk(KERN_WARNING "CIFS: prefix too long\n");
-                               goto cifs_parse_mount_err;
-                       }
-
-                       vol->prepath = kmalloc(temp_len+1, GFP_KERNEL);
-                       if (vol->prepath == NULL) {
-                               printk(KERN_WARNING "CIFS: no memory "
-                                                   "for path prefix\n");
-                               goto cifs_parse_mount_err;
-                       }
-
-                       if (string[0] != '/') {
-                               vol->prepath[0] = '/';
-                               strcpy(vol->prepath+1, string);
-                       } else
-                               strcpy(vol->prepath, string);
+                       /* skip over any leading delimiter */
+                       if (*args[0].from == '/' || *args[0].from == '\\')
+                               args[0].from++;
 
+                       kfree(vol->prepath);
+                       vol->prepath = match_strdup(args);
+                       if (vol->prepath == NULL)
+                               goto out_nomem;
                        break;
                case Opt_iocharset:
                        string = match_strdup(args);
@@ -3236,7 +3219,7 @@ build_unc_path_to_root(const struct smb_vol *vol,
                const struct cifs_sb_info *cifs_sb)
 {
        char *full_path, *pos;
-       unsigned int pplen = vol->prepath ? strlen(vol->prepath) : 0;
+       unsigned int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;
        unsigned int unc_len = strnlen(vol->UNC, MAX_TREE_SIZE + 1);
 
        full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
@@ -3247,6 +3230,7 @@ build_unc_path_to_root(const struct smb_vol *vol,
        pos = full_path + unc_len;
 
        if (pplen) {
+               *pos++ = CIFS_DIR_SEP(cifs_sb);
                strncpy(pos, vol->prepath, pplen);
                pos += pplen;
        }

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 3b7e0c1266f7d86805a740a9ad4f711c96c9b85a..8719bbe0dcc36e32836cef3cf0b2b9c6e8a8175a 100644 (file)
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -48,7 +48,7 @@ char *
 cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
                        struct cifs_tcon *tcon)
 {
-       int pplen = vol->prepath ? strlen(vol->prepath) : 0;
+       int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;
        int dfsplen;
        char *full_path = NULL;
 
@@ -69,7 +69,8 @@ cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
 
        if (dfsplen)
                strncpy(full_path, tcon->treeName, dfsplen);
-       strncpy(full_path + dfsplen, vol->prepath, pplen);
+       full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
+       strncpy(full_path + dfsplen + 1, vol->prepath, pplen);
        convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
        full_path[dfsplen + pplen] = 0; /* add trailing null */
        return full_path;