Fix bug #7996 - sgid bit lost on folder rename.

[ira/wip.git] / source3 / smbd / dosmode.c

diff --git a/source3/smbd/dosmode.c b/source3/smbd/dosmode.c
index 0e45e88d8ddd9e1d3b1ca922565d5d365b5ee3aa..1ea4c686d51a02469e0d88d8cb83b8bd40a8edb3 100644 (file)
--- a/source3/smbd/dosmode.c
+++ b/source3/smbd/dosmode.c
@@ -798,6 +798,27 @@ int file_set_dosmode(connection_struct *conn, struct smb_filename *smb_fname,
                unixmode |= (smb_fname->st.st_ex_mode & (S_IWUSR|S_IWGRP|S_IWOTH));
        }
 
+       /*
+        * From the chmod 2 man page:
+        *
+        * "If the calling process is not privileged, and the group of the file
+        * does not match the effective group ID of the process or one of its
+        * supplementary group IDs, the S_ISGID bit will be turned off, but
+        * this will not cause an error to be returned."
+        *
+        * Simply refuse to do the chmod in this case.
+        */
+
+       if (S_ISDIR(smb_fname->st.st_ex_mode) && (unixmode & S_ISGID) &&
+                       geteuid() != sec_initial_uid() &&
+                       !current_user_in_group(conn, smb_fname->st.st_ex_gid)) {
+               DEBUG(3,("file_set_dosmode: setgid bit cannot be "
+                       "set for directory %s\n",
+                       smb_fname_str_dbg(smb_fname)));
+               errno = EPERM;
+               return -1;
+       }
+
        ret = SMB_VFS_CHMOD(conn, smb_fname->base_name, unixmode);
        if (ret == 0) {
                if(!newfile || (lret != -1)) {