[PATCH 2/3] cifs: tighten up default file_mode/dir_mode
Jeff Layton <[email protected]>
| Newsgroups | gmane.linux.file-systems.cifs |
|---|---|
| Message-ID | <[email protected]> |
The current default file mode is 02767 and dir mode is 0777. This is extremely "loose". Given that CIFS is a single-user protocol, these permissions allow anyone to use the mount -- in effect, giving anyone on the machine access to the credentials used to mount the share. Change this by making the default permissions restrict access to only the uid of the share. Note that this patch also removes the mandatory locking flags from the default file_mode. After having looked at how these flags are used by the kernel, I don't think that keeping them as the default offers any real benefit. That flag combination makes it so that the kernel enforces mandatory locking. Since the server is going to do that for us anyway, I don't think we want the client to enforce this by default on applications that just want advisory locks. Anyone that does want this behavior can always enable it by setting the file_mode appropriately. Signed-off-by: Jeff Layton <[email protected]> --- fs/cifs/connect.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 4f5a03c..c8f4cc2 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -827,9 +827,9 @@ cifs_parse_mount_options(char *options, const char *devname, vol->target_rfc1001_name[0] = 0; vol->linux_uid = current_uid(); /* use current_euid() instead? */ vol->linux_gid = current_gid(); - vol->dir_mode = S_IRWXUGO; - /* 2767 perms indicate mandatory locking support */ - vol->file_mode = (S_IRWXUGO | S_ISGID) & (~S_IXGRP); + + /* default to only allowing access to owner of the mount */ + vol->dir_mode = vol->file_mode = S_IRWXU; /* vol->retry default is 0 (i.e. "soft" limited retry not hard retry) */ vol->rw = true; -- 1.6.0.6