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authorPieter Wuille <pieter.wuille@gmail.com>2017-07-17 11:00:40 -0700
committerPieter Wuille <pieter.wuille@gmail.com>2017-07-17 15:12:39 -0700
commitfee0d803fb55c8d85b5cd1ff69d799c5ad522e18 (patch)
tree09ea2c2d3e2ae0c7973a9e90c7f62c73b6edc995 /src/merkleblock.cpp
parent0b019357ff09e7a522307fc271d6b60562a7b890 (diff)
parent8276e70de15c5c3a7525471ad619edd1237b424a (diff)
Merge #9980: Fix mem access violation merkleblock
8276e70de Adding assert to avoid a memory access violation inside of PartialMerkleTree::CalcHash() (Chris Stewart) Pull request description: Fixing a possible memory access violation in CPartialMerkleTree::CalcHash(). This can happen if we some how a merkle tree with zero txids. I don't think this can happen in practice as we only send merkle block messages on the p2p network as of now -- we cannot receive them. This was found with #8469, specifically using this [generator](https://github.com/Christewart/bitcoin/blob/rapidcheck/src/test/gen/merkleblock_gen.h#L52-L77) which will cause a memory access violation on [this test case](https://github.com/Christewart/bitcoin/blob/rapidcheck/src/test/merkleblock_properties.cpp#L48). Tree-SHA512: b95904ec45ea3f082c7722161d93ee06b24c706fbffa909a6e995ed14788aed2830f91b626da6f0347660c45874a0735dab61c9440b59c949c690af4165c83fb
Diffstat (limited to 'src/merkleblock.cpp')
-rw-r--r--src/merkleblock.cpp3
1 files changed, 3 insertions, 0 deletions
diff --git a/src/merkleblock.cpp b/src/merkleblock.cpp
index ba5f7b400c..f0abea0611 100644
--- a/src/merkleblock.cpp
+++ b/src/merkleblock.cpp
@@ -59,6 +59,9 @@ CMerkleBlock::CMerkleBlock(const CBlock& block, const std::set<uint256>& txids)
}
uint256 CPartialMerkleTree::CalcHash(int height, unsigned int pos, const std::vector<uint256> &vTxid) {
+ //we can never have zero txs in a merkle block, we always need the coinbase tx
+ //if we do not have this assert, we can hit a memory access violation when indexing into vTxid
+ assert(vTxid.size() != 0);
if (height == 0) {
// hash at height 0 is the txids themself
return vTxid[pos];