From: Daniel P. Berrangé <berrange@redhat.com>
Date: Mon, 30 Sep 2019 11:39:17 +0000 (+0100)
Subject: qemu: sanity check vhost user FD before passing to QEMU
X-Git-Tag: v5.8.0-rc1~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6ffb8fff9e0a4fd22b303ecc8dbd6a3d8c61c2a4;p=thirdparty%2Flibvirt.git

qemu: sanity check vhost user FD before passing to QEMU

Ensure that the FD we're passing to QEMU is actually open, so we get a
sane error message upfront instead of telling QEMU to use a closed FD.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 77470a6037..8c979fdf65 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4704,6 +4704,12 @@ qemuBuildVhostUserChardevStr(const char *alias,
 {
     char *chardev = NULL;
 
+    if (*fd == -1) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Attempt to pass closed vhostuser FD"));
+        return NULL;
+    }
+
     if (virAsprintf(&chardev, "socket,id=chr-vu-%s,fd=%d", alias, *fd) < 0)
         return NULL;