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Kernel: VERIFY that addresses passed to kfree_sized() look valid

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Let's do some simple pointer arithmetic to verify that the address being
freed is at least within one of the two valid kmalloc VM ranges.
This commit is contained in:
Andreas Kling
2021-12-28 19:25:14 +01:00
parent 9111376d70
commit 9dffcc9752
1 changed files with 12 additions and 0 deletions
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12
Kernel/Heap/kmalloc.cpp
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@@ -186,6 +186,7 @@ struct KmallocGlobalData {
void deallocate(void* ptr, size_t size)
{
VERIFY(!expansion_in_progress);
VERIFY(is_valid_kmalloc_address(VirtualAddress { ptr }));
for (auto& slabheap : slabheaps) {
if (size <= slabheap.slab_size())
@@ -298,6 +299,17 @@ struct KmallocGlobalData {
};
Optional<ExpansionData> expansion_data;
bool is_valid_kmalloc_address(VirtualAddress vaddr) const
{
if (vaddr.as_ptr() >= initial_kmalloc_memory && vaddr.as_ptr() < (initial_kmalloc_memory + INITIAL_KMALLOC_MEMORY_SIZE))
return true;
if (!expansion_data.has_value())
return false;
return expansion_data->virtual_range.contains(vaddr);
}
KmallocSubheap::List subheaps;
KmallocSlabheap slabheaps[6] = { 16, 32, 64, 128, 256, 512 };