[PATCH 26/47] hw/smbios: fix field corruption in type 4 table

[Michael Tokarev]

From: Julia Suvorova <jusual@redhat.com>

Since table type 4 of SMBIOS version 2.6 is shorter than 3.0, the
strings which follow immediately after the struct fields have been
overwritten by unconditional filling of later fields such as core_count2.
Make these fields dependent on the SMBIOS version.

Fixes: 05e27d74c7 ("hw/smbios: add core_count2 to smbios table type 4")
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2169904

Signed-off-by: Julia Suvorova <jusual@redhat.com>
Message-Id: <20230223125747.254914-1-jusual@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 60d09b8dc7dd4256d664ad680795cb1327805b2b)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
---
 hw/smbios/smbios.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
index b4243de735..66a020999b 100644
--- a/hw/smbios/smbios.c
+++ b/hw/smbios/smbios.c
@@ -749,14 +749,16 @@ static void smbios_build_type_4_table(MachineState *ms, 
unsigned instance)
     t->core_count = (ms->smp.cores > 255) ? 0xFF : ms->smp.cores;
     t->core_enabled = t->core_count;
 
-    t->core_count2 = t->core_enabled2 = cpu_to_le16(ms->smp.cores);
-
     t->thread_count = (ms->smp.threads > 255) ? 0xFF : ms->smp.threads;
-    t->thread_count2 = cpu_to_le16(ms->smp.threads);
 
     t->processor_characteristics = cpu_to_le16(0x02); /* Unknown */
     t->processor_family2 = cpu_to_le16(0x01); /* Other */
 
+    if (tbl_len == SMBIOS_TYPE_4_LEN_V30) {
+        t->core_count2 = t->core_enabled2 = cpu_to_le16(ms->smp.cores);
+        t->thread_count2 = cpu_to_le16(ms->smp.threads);
+    }
+
     SMBIOS_BUILD_TABLE_POST;
     smbios_type4_count++;
 }
-- 
2.30.2