File 0216-9pfs-remove-side-effects-in-local_o.patch of Package qemu.12301

From bc4a56eb3d75bfe1bdfa9375f2d9106a3fe74a97 Mon Sep 17 00:00:00 2001
From: Greg Kurz <groug@kaod.org>
Date: Sun, 26 Feb 2017 23:41:55 +0100
Subject: [PATCH] 9pfs: remove side-effects in local_open() and local_opendir()

If these functions fail, they should not change *fs. Let's use local
variables to fix this.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 21328e1e57f526e3f0c2fcd00f10c8aa6e7bc07f)
[BR: Fix and/or infrastructure for BSC#1020427 CVE-2016-9602]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/9pfs/9p-local.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 1f9558dfdc..62589c7d91 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -353,10 +353,15 @@ static int local_open(FsContext *ctx, V9fsPath *fs_path,
 {
     char *buffer;
     char *path = fs_path->data;
+    int fd;
 
     buffer = rpath(ctx, path);
-    fs->fd = open(buffer, flags | O_NOFOLLOW);
+    fd = open(buffer, flags | O_NOFOLLOW);
     g_free(buffer);
+    if (fd == -1) {
+        return -1;
+    }
+    fs->fd = fd;
     return fs->fd;
 }
 
@@ -365,13 +370,15 @@ static int local_opendir(FsContext *ctx,
 {
     char *buffer;
     char *path = fs_path->data;
+    DIR *stream;
 
     buffer = rpath(ctx, path);
-    fs->dir.stream = opendir(buffer);
+    stream = opendir(buffer);
     g_free(buffer);
-    if (!fs->dir.stream) {
+    if (!stream) {
         return -1;
     }
+    fs->dir.stream = stream;
     return 0;
 }