From: Cédric Le Goater <clg@kaod.org>
Date: Tue, 2 Nov 2021 16:29:05 +0000 (+0100)
Subject: ppc/pnv: Fix check on block device before updating drive contents
X-Git-Tag: qemu-xen-4.17.0-rc4~234^2~28
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=957c52aed5efcf036affb30907514262643f556a;p=qemu-xen.git

ppc/pnv: Fix check on block device before updating drive contents

Test is wrong and the backend can never updated. It could have led to
a QEMU crash but since the firmware deactivates flash access if a valid
layout is not detected, it went unnoticed.

Reported-by: Coverity CID 1465223
Fixes: 35dde5766211 ("ppc/pnv: Add a PNOR model")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211102162905.762078-1-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

diff --git a/hw/ppc/pnv_pnor.c b/hw/ppc/pnv_pnor.c
index 5ef1cf2afb..83ecccca28 100644
--- a/hw/ppc/pnv_pnor.c
+++ b/hw/ppc/pnv_pnor.c
@@ -36,7 +36,7 @@ static void pnv_pnor_update(PnvPnor *s, int offset, int size)
     int offset_end;
     int ret;
 
-    if (s->blk) {
+    if (!s->blk || !blk_is_writable(s->blk)) {
         return;
     }