[PATCH] hw/arm/ax3000-soc: fix heap overflow from missing class_size

TYPE_AX3000_SOC declares an Ax3000SoCClass via OBJECT_DECLARE_TYPE() and
ax3000_class_init() writes to it:

    Ax3000SoCClass *sc = AX3000_SOC_CLASS(oc);
    sc->num_cpus = AX3000_NUM_CPUS;

but its TypeInfo omits .class_size, so type_initialize() only allocates
class_size inherited from the parent, i.e. sizeof(SysBusDeviceClass).
The store to sc->num_cpus therefore writes 4 bytes of the value 4 just
past the end of the class allocation, corrupting whatever heap block
follows it.

Fix by setting class_size.

Fixes: 33a71a68c6e1 ("hw/arm: Add Axiado SoC AX3000")
Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/4197
Signed-off-by: Doug Cook <[email protected]>
---
 hw/arm/ax3000-soc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/arm/ax3000-soc.c b/hw/arm/ax3000-soc.c
index 71e31c6fb4..ebe174fb97 100644
--- a/hw/arm/ax3000-soc.c
+++ b/hw/arm/ax3000-soc.c
@@ -236,6 +236,7 @@ static const TypeInfo axiado_soc_types[] = {
         .instance_size  = sizeof(Ax3000SoCState),
         .instance_init  = ax3000_init,
         .class_init     = ax3000_class_init,
+        .class_size     = sizeof(Ax3000SoCClass),
     }
 };
 
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2.55.0.vfs.0.3