From bbf2faa6992ff1a2f0b84625756f615fd117c93d Mon Sep 17 00:00:00 2001
From: Facundo Medica <14063057+facundomedica@users.noreply.github.com>
Date: Mon, 23 Oct 2023 16:12:52 +0200
Subject: [PATCH] fix(math): NewUintFromBigInt argument mutation (#18214)

---
 math/CHANGELOG.md |  1 +
 math/uint.go      |  2 +-
 math/uint_test.go | 10 ++++++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/math/CHANGELOG.md b/math/CHANGELOG.md
index ebe9a28a85ac..68a0cffed10b 100644
--- a/math/CHANGELOG.md
+++ b/math/CHANGELOG.md
@@ -42,6 +42,7 @@ Ref: https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.j
 
 ### Bug Fixes
 
+* [#18214](https://github.com/cosmos/cosmos-sdk/pull/18214) Ensure that modifying the argument to `NewUIntFromBigInt` doesn't mutate the returned value.
 * [#18211](https://github.com/cosmos/cosmos-sdk/pull/18211) RelativePow now returns 1 when 0^0, before it was returning the scale factor.
 * [#17725](https://github.com/cosmos/cosmos-sdk/pull/17725) Fix state break in ApproxRoot. This has been present since math/v1.0.1. It changed the rounding behavior at precision end in an intermediary division from banker's to truncation. The truncation occurs from binary right shift in the case of square roots. The change is now reverted back to banker's rounding universally for any root.
 
diff --git a/math/uint.go b/math/uint.go
index 6d9de72190b2..85906047bff1 100644
--- a/math/uint.go
+++ b/math/uint.go
@@ -235,7 +235,7 @@ func checkNewUint(i *big.Int) (Uint, error) {
 	if err := UintOverflow(i); err != nil {
 		return Uint{}, err
 	}
-	return Uint{i}, nil
+	return Uint{new(big.Int).Set(i)}, nil
 }
 
 // RelativePow raises x to the power of n, where x (and the result, z) are scaled by factor b
diff --git a/math/uint_test.go b/math/uint_test.go
index 0c464433a074..3ae815e0e662 100644
--- a/math/uint_test.go
+++ b/math/uint_test.go
@@ -261,6 +261,16 @@ func (s *uintTestSuite) TestParseUint() {
 	}
 }
 
+func (s *uintTestSuite) TestNewUintFromBigInt() {
+	r := big.NewInt(42)
+	i := sdkmath.NewUintFromBigInt(r)
+	s.Require().Equal(r, i.BigInt())
+
+	// modify r and ensure i doesn't change
+	r = r.SetInt64(100)
+	s.Require().NotEqual(r, i.BigInt())
+}
+
 func randuint() sdkmath.Uint {
 	return sdkmath.NewUint(rand.Uint64())
 }