From f75ed59f40bed3ce94adad4b3ebbb7bfacfdf4ab Mon Sep 17 00:00:00 2001
From: Dmitry Frolov <frolov@swemel.ru>
Date: Tue, 10 Oct 2023 13:48:53 +0300
Subject: [PATCH] migration: fix RAMBlock add NULL check

qemu_ram_block_from_host() may return NULL, which will be dereferenced w/o
check. Usualy return value is checked for this function.
Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Dmitry Frolov <frolov@swemel.ru>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231010104851.802947-1-frolov@swemel.ru>
---
 migration/ram.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/migration/ram.c b/migration/ram.c
index 24d91de8b3..e8df4dc862 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -4285,6 +4285,11 @@ static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host,
     RAMBlock *rb = qemu_ram_block_from_host(host, false, &offset);
     Error *err = NULL;
 
+    if (!rb) {
+        error_report("RAM block not found");
+        return;
+    }
+
     if (migrate_ram_is_ignored(rb)) {
         return;
     }