softmmu: Assert data in bounds in iotlb_to_section

Acked-by: Alex Bennée <[email protected]> Suggested-by: Alex Bennée <[email protected]> Signed-off-by: Richard Henderson <[email protected]> (cherry picked from commit 86e4f93) Signed-off-by: Michael Tokarev <[email protected]>
lowRISC · Aug 30, 2023 · 5691fbf · 5691fbf
1 parent 441106e
commit 5691fbf
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
@@ -2413,9 +2413,15 @@ MemoryRegionSection *iotlb_to_section(CPUState *cpu,
     int asidx = cpu_asidx_from_attrs(cpu, attrs);
     CPUAddressSpace *cpuas = &cpu->cpu_ases[asidx];
     AddressSpaceDispatch *d = qatomic_rcu_read(&cpuas->memory_dispatch);
-    MemoryRegionSection *sections = d->map.sections;
+    int section_index = index & ~TARGET_PAGE_MASK;
+    MemoryRegionSection *ret;
+
+    assert(section_index < d->map.sections_nb);
+    ret = d->map.sections + section_index;
+    assert(ret->mr);
+    assert(ret->mr->ops);
 
-    return &sections[index & ~TARGET_PAGE_MASK];
+    return ret;
 }
 
 static void io_mem_init(void)