disable most mode changes on non-unix/non-cifsacl mounts
CIFS currently allows you to change the mode of an inode on a share that
doesn't have unix extensions enabled, and isn't using cifsacl. The inode
in this case *only* has its mode changed in memory on the client. This
is problematic since it can change any time the inode is purged from the
cache.
This patch makes cifs_setattr silently ignore most mode changes when
unix extensions and cifsacl support are not enabled, and when the share
is not mounted with the "dynperm" option. The exceptions are:
When a mode change would remove all write access to an inode we turn on
the ATTR_READONLY bit on the server and remove all write bits from the
inode's mode in memory.
When a mode change would add a write bit to an inode that previously had
them all turned off, it turns off the ATTR_READONLY bit on the server,
and resets the mode back to what it would normally be (generally, the
file_mode or dir_mode of the share).
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index fe752fd..722be54 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1575,7 +1575,7 @@
attrs->ia_valid &= ~ATTR_MODE;
if (attrs->ia_valid & ATTR_MODE) {
- cFYI(1, ("Mode changed to 0x%x", attrs->ia_mode));
+ cFYI(1, ("Mode changed to 0%o", attrs->ia_mode));
mode = attrs->ia_mode;
}
@@ -1590,18 +1590,18 @@
#ifdef CONFIG_CIFS_EXPERIMENTAL
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
rc = mode_to_acl(inode, full_path, mode);
- else if ((mode & S_IWUGO) == 0) {
-#else
- if ((mode & S_IWUGO) == 0) {
+ else
#endif
- /* not writeable */
- if ((cifsInode->cifsAttrs & ATTR_READONLY) == 0) {
- set_dosattr = true;
- time_buf.Attributes =
- cpu_to_le32(cifsInode->cifsAttrs |
- ATTR_READONLY);
- }
- } else if (cifsInode->cifsAttrs & ATTR_READONLY) {
+ if (((mode & S_IWUGO) == 0) &&
+ (cifsInode->cifsAttrs & ATTR_READONLY) == 0) {
+ set_dosattr = true;
+ time_buf.Attributes = cpu_to_le32(cifsInode->cifsAttrs |
+ ATTR_READONLY);
+ /* fix up mode if we're not using dynperm */
+ if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) == 0)
+ attrs->ia_mode = inode->i_mode & ~S_IWUGO;
+ } else if ((mode & S_IWUGO) &&
+ (cifsInode->cifsAttrs & ATTR_READONLY)) {
/* If file is readonly on server, we would
not be able to write to it - so if any write
bit is enabled for user or group or other we
@@ -1612,6 +1612,20 @@
/* Windows ignores set to zero */
if (time_buf.Attributes == 0)
time_buf.Attributes |= cpu_to_le32(ATTR_NORMAL);
+
+ /* reset local inode permissions to normal */
+ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)) {
+ attrs->ia_mode &= ~(S_IALLUGO);
+ if (S_ISDIR(inode->i_mode))
+ attrs->ia_mode |=
+ cifs_sb->mnt_dir_mode;
+ else
+ attrs->ia_mode |=
+ cifs_sb->mnt_file_mode;
+ }
+ } else if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)) {
+ /* ignore mode change - ATTR_READONLY hasn't changed */
+ attrs->ia_valid &= ~ATTR_MODE;
}
}