[PATCH] vfs_streams_xattr: Fix segfault when running with log level 10

[Christof Schmitt]

From f9e34849b344883441796c7a34bf234482ac8db9 Mon Sep 17 00:00:00 2001
From: Christof Schmitt <cs at samba.org>
Date: Wed, 13 Sep 2017 16:23:53 -0700
Subject: [PATCH] vfs_streams_xattr: Fix segfault when running with log level
 10

This happens when vfs_streams_xattr is loaded, log level is set to 10
and the default stream of a file or directory is accessed. In that case
streams_xattr_open does not allocate the stream_io fsp extension. The
DBG_DEBUG message in streams_xattr_fstat tries to access the stream_io
before checking for a NULL value, resulting in the crash. Fix this by
moving the debug message after the check for a NULL pointer.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13032

Signed-off-by: Christof Schmitt <cs at samba.org>
---
 source3/modules/vfs_streams_xattr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source3/modules/vfs_streams_xattr.c b/source3/modules/vfs_streams_xattr.c
index 1b0b577..f75f6a1 100644
--- a/source3/modules/vfs_streams_xattr.c
+++ b/source3/modules/vfs_streams_xattr.c
@@ -232,12 +232,12 @@ static int streams_xattr_fstat(vfs_handle_struct *handle, files_struct *fsp,
 	struct stream_io *io = (struct stream_io *)
 		VFS_FETCH_FSP_EXTENSION(handle, fsp);
 
-	DBG_DEBUG("streams_xattr_fstat called for %s\n", fsp_str_dbg(io->fsp));
-
 	if (io == NULL || fsp->base_fsp == NULL) {
 		return SMB_VFS_NEXT_FSTAT(handle, fsp, sbuf);
 	}
 
+	DBG_DEBUG("streams_xattr_fstat called for %s\n", fsp_str_dbg(io->fsp));
+
 	if (!streams_xattr_recheck(io)) {
 		return -1;
 	}
-- 
1.8.3.1