From e3f714aa2aee5f4a52671de30f48911edf042ea9 Mon Sep 17 00:00:00 2001 From: moneromooo-monero Date: Thu, 4 Apr 2019 00:15:07 +0000 Subject: [PATCH] tree-hash: allocate variable memory on heap, not stack Large amounts might run out of stack Reported by guidov --- src/crypto/tree-hash.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/src/crypto/tree-hash.c b/src/crypto/tree-hash.c index 7802fb67f..0a5860f3b 100644 --- a/src/crypto/tree-hash.c +++ b/src/crypto/tree-hash.c @@ -30,6 +30,7 @@ #include #include +#include #include #include "hash-ops.h" @@ -82,23 +83,24 @@ void tree_hash(const char (*hashes)[HASH_SIZE], size_t count, char *root_hash) { size_t cnt = tree_hash_cnt( count ); - char ints[cnt][HASH_SIZE]; - memset(ints, 0 , sizeof(ints)); // zero out as extra protection for using uninitialized mem + char *ints = calloc(cnt, HASH_SIZE); // zero out as extra protection for using uninitialized mem + assert(ints); memcpy(ints, hashes, (2 * cnt - count) * HASH_SIZE); for (i = 2 * cnt - count, j = 2 * cnt - count; j < cnt; i += 2, ++j) { - cn_fast_hash(hashes[i], 64, ints[j]); + cn_fast_hash(hashes[i], 64, ints + j * HASH_SIZE); } assert(i == count); while (cnt > 2) { cnt >>= 1; for (i = 0, j = 0; j < cnt; i += 2, ++j) { - cn_fast_hash(ints[i], 64, ints[j]); + cn_fast_hash(ints + i * HASH_SIZE, 64, ints + j * HASH_SIZE); } } - cn_fast_hash(ints[0], 64, root_hash); + cn_fast_hash(ints, 64, root_hash); + free(ints); } }