if (Header->Reserved != 0)
return false;
- // Check the number of buckets.
+ // Check the number of buckets. It should be a power of two, and there
+ // should be enough space in the file for all of them.
auto NumBuckets = NeedsByteSwap
? llvm::sys::getSwappedBytes(Header->NumBuckets)
: Header->NumBuckets;
-
- // If the number of buckets is not a power of two, the headermap is corrupt.
if (NumBuckets & (NumBuckets - 1))
return false;
+ if (File.getBufferSize() <
+ sizeof(HMapHeader) + sizeof(HMapBucket) * NumBuckets)
+ return false;
// Okay, everything looks good.
return true;
/// bswap'ing its fields as appropriate. If the bucket number is not valid,
/// this return a bucket with an empty key (0).
HMapBucket HeaderMapImpl::getBucket(unsigned BucketNo) const {
+ assert(FileBuffer->getBufferSize() >=
+ sizeof(HMapHeader) + sizeof(HMapBucket) * BucketNo &&
+ "Expected bucket to be in range");
+
HMapBucket Result;
Result.Key = HMAP_EmptyBucketKey;
const HMapBucket *BucketArray =
reinterpret_cast<const HMapBucket*>(FileBuffer->getBufferStart() +
sizeof(HMapHeader));
-
const HMapBucket *BucketPtr = BucketArray+BucketNo;
- if ((const char*)(BucketPtr+1) > FileBuffer->getBufferEnd()) {
- Result.Prefix = 0;
- Result.Suffix = 0;
- return Result; // Invalid buffer, corrupt hmap.
- }
- // Otherwise, the bucket is valid. Load the values, bswapping as needed.
+ // Load the values, bswapping as needed.
Result.Key = getEndianAdjustedWord(BucketPtr->Key);
Result.Prefix = getEndianAdjustedWord(BucketPtr->Prefix);
Result.Suffix = getEndianAdjustedWord(BucketPtr->Suffix);