Kernel: Fix possible buffer overrun when scanning a MappedROM

If the length of the prefix was less than the chunk_size argument
we were potentionally reading past the mapped memory region.
This commit is contained in:
Tom 2022-01-02 16:25:08 -07:00 committed by Linus Groh
parent e70aa690d2
commit 190572b714
Notes: sideshowbarker 2024-07-17 21:41:23 +09:00

View file

@ -23,7 +23,10 @@ public:
Optional<PhysicalAddress> find_chunk_starting_with(StringView prefix, size_t chunk_size) const
{
for (auto* candidate = base(); candidate < end(); candidate += chunk_size) {
auto prefix_length = prefix.length();
if (size < prefix_length)
return {};
for (auto* candidate = base(); candidate <= end() - prefix_length; candidate += chunk_size) {
if (!__builtin_memcmp(prefix.characters_without_null_termination(), candidate, prefix.length()))
return paddr_of(candidate);
}