From a469204134ed3978af6f164b56f9ea58a51425a3 Mon Sep 17 00:00:00 2001
From: Benedikt <crypto@benedikt-wagner.dev>
Date: Thu, 12 Oct 2023 15:24:26 +0200
Subject: [PATCH] arg check overflow

---
 src/modules/schnorrsig/main_impl.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/modules/schnorrsig/main_impl.h b/src/modules/schnorrsig/main_impl.h
index 00ce48119..eae6c45ad 100644
--- a/src/modules/schnorrsig/main_impl.h
+++ b/src/modules/schnorrsig/main_impl.h
@@ -298,6 +298,7 @@ int secp256k1_schnorrsig_inc_aggregate(const secp256k1_context *ctx, unsigned ch
 
     /* Check that aggsig_size is large enough, i.e. aggsig_size >= 32*(n+1) */
     n = n_before + n_new;
+    ARG_CHECK(n >= n_before);
     if ((*aggsig_size / 32) <= 0 || ((*aggsig_size / 32)-1) < n) {
         return 0;
     }