@@ -126,20 +126,20 @@ static int alloc_metrics(PullupContext *s, PullupField *f)

     return 0;

 }

-static void free_field_queue(PullupField *head, PullupField **last)

+static void free_field_queue(PullupField *head)

 {

     PullupField *f = head;

-    while (f) {

+    do {

+        PullupField *next;

+        if (!f)

+            break;

         av_free(f->diffs);

         av_free(f->combs);

         av_free(f->vars);

-        if (f == *last) {

-            av_freep(last);

-            break;

-        }

-        f = f->next;

-        av_freep(&f->prev);

-    };

+        next = f->next;

+        av_free(f);

+        f = next;

+    } while (f != head);

 }

 static PullupField *make_field_queue(PullupContext *s, int len)

@@ -158,14 +158,14 @@ static PullupField *make_field_queue(PullupContext *s, int len)

     for (; len > 0; len--) {

         f->next = av_mallocz(sizeof(*f->next));

         if (!f->next) {

-            free_field_queue(head, &f);

+            free_field_queue(head);

             return NULL;

         }

         f->next->prev = f;

         f = f->next;

         if (alloc_metrics(s, f) < 0) {

-            free_field_queue(head, &f);

+            free_field_queue(head);

             return NULL;

         }

     }

@@ -736,7 +736,8 @@ static av_cold void uninit(AVFilterContext *ctx)

     PullupContext *s = ctx->priv;

     int i;

-    free_field_queue(s->head, &s->last);

+    free_field_queue(s->head);

+    s->last = NULL;

     for (i = 0; i < FF_ARRAY_ELEMS(s->buffers); i++) {

         av_freep(&s->buffers[i].planes[0]);