From 3a45bed07499e8bf3c0717084722f5247b9b1cc2 Mon Sep 17 00:00:00 2001
From: Arpit Jain <arpitjain099@gmail.com>
Date: Sun, 28 Jun 2026 12:30:28 +0900
Subject: [PATCH] fix(meta): RemoveFinalizer handles duplicate finalizers
 without panicking

RemoveFinalizer mutated the finalizer slice in place while ranging over
it by index. range evaluates len(f) once at loop start, but the
append(f[:i], f[i+1:]...) call shrinks f in place, so after a removal the
loop keeps walking original indices into the now-shorter backing array.
When the target finalizer appears more than once this either panics with
slice bounds out of range or silently leaves one occurrence behind.

Replace the index-mutating loop with slices.DeleteFunc, which removes all
matching elements correctly in a single pass. The slices package is
already imported and used by the sibling AddFinalizer/FinalizerExists.

Add regression cases for duplicate finalizers to TestRemoveFinalizer.

Signed-off-by: Arpit Jain <arpitjain099@gmail.com>
---
 pkg/meta/meta.go      |  8 +++-----
 pkg/meta/meta_test.go | 22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/pkg/meta/meta.go b/pkg/meta/meta.go
index ac729b7f2..1e14c4176 100644
--- a/pkg/meta/meta.go
+++ b/pkg/meta/meta.go
@@ -190,11 +190,9 @@ func AddFinalizer(o metav1.Object, finalizer string) {
 // RemoveFinalizer from the supplied Kubernetes object's metadata.
 func RemoveFinalizer(o metav1.Object, finalizer string) {
 	f := o.GetFinalizers()
-	for i, e := range f {
-		if e == finalizer {
-			f = append(f[:i], f[i+1:]...)
-		}
-	}
+	f = slices.DeleteFunc(f, func(e string) bool {
+		return e == finalizer
+	})
 
 	o.SetFinalizers(f)
 }
diff --git a/pkg/meta/meta_test.go b/pkg/meta/meta_test.go
index e68034421..7bc249011 100644
--- a/pkg/meta/meta_test.go
+++ b/pkg/meta/meta_test.go
@@ -538,6 +538,28 @@ func TestRemoveFinalizer(t *testing.T) {
 			},
 			want: []string{funalizer},
 		},
+		"DuplicateFinalizersExist": {
+			args: args{
+				o: &corev1.Pod{
+					ObjectMeta: metav1.ObjectMeta{
+						Finalizers: []string{finalizer, finalizer},
+					},
+				},
+				finalizer: finalizer,
+			},
+			want: []string{},
+		},
+		"DuplicateFinalizersWithOther": {
+			args: args{
+				o: &corev1.Pod{
+					ObjectMeta: metav1.ObjectMeta{
+						Finalizers: []string{finalizer, funalizer, finalizer},
+					},
+				},
+				finalizer: finalizer,
+			},
+			want: []string{funalizer},
+		},
 	}
 
 	for name, tc := range cases {