2012/11/16 Jeff Layton <jlayton@xxxxxxxxxx>:
> 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?
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/cifs/connect.c | 34 +++++++++-------------------------
> fs/cifs/smb1ops.c | 5 +++--
> fs/cifs/smb2ops.c | 2 +-
> 3 files changed, 13 insertions(+), 28 deletions(-)
>
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 89f426f..b1f352a 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -1603,31 +1603,14 @@ 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);
> @@ -3238,7 +3221,7 @@ 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);
> @@ -3249,6 +3232,7 @@ 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/smb1ops.c b/fs/cifs/smb1ops.c
> index 56cc4be..50e9613 100644
> --- a/fs/cifs/smb1ops.c
> +++ b/fs/cifs/smb1ops.c
> @@ -579,7 +579,7 @@ static 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;
>
> @@ -600,7 +600,8 @@ 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;
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 4d9dbe0..1baa82d 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -266,7 +266,7 @@ static char *
> smb2_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;
> char *full_path = NULL;
>
> /* if no prefix path, simply set path to the root of share to "" */
> --
> 1.7.11.7
>
> --
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Reviewed-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
--
Best regards,
Pavel Shilovsky.
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