smbd: let unix_convert() fail early if initial stat fails with EACCES

Doing directory scans on the path components is not going to change this, so
give up early. No change in behaviour, as we would just fail later in
get_real_filename() otherwise.

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Wed Apr 22 21:08:39 UTC 2020 on sn-devel-184

diff --git a/source3/smbd/filename.c b/source3/smbd/filename.c
index 9faff9da45afc237c2f92cd72880a060c2da5f00..8030e50431720a6899d6cf4510411b9ff612cc75 100644 (file)
--- a/source3/smbd/filename.c
+++ b/source3/smbd/filename.c
@@ -700,6 +700,18 @@ NTSTATUS unix_convert(TALLOC_CTX *ctx,
                /* Stat failed - ensure we don't use it. */
                SET_STAT_INVALID(smb_fname->st);
 
+               if (errno == EACCES) {
+                       /*
+                        * Early exit on access denied. Walking
+                        * the path won't fix that.
+                        */
+                       DBG_DEBUG("stat [%s]: %s\n",
+                                 smb_fname_str_dbg(smb_fname),
+                                 strerror(errno));
+                       status = NT_STATUS_ACCESS_DENIED;
+                       goto fail;
+               }
+
                if (errno == ENOENT) {
                        /* Optimization when creating a new file - only
                           the last component doesn't exist.