src/http/modules/ngx_http_limit_req_module.c:604: error: Integer Overflow L2
  ([0, +oo] - 64):unsigned64 by call to `ngx_slab_free_locked`.

src/http/modules/ngx_http_limit_req_module.c:604:9: Call
602.         ngx_rbtree_delete(&ctx->sh->rbtree, node);
603. 
604.         ngx_slab_free_locked(ctx->shpool, node);
             ^
605.     }
606. }

src/core/ngx_slab.c:457:1: Parameter `pool->stats->total`
  455. 
  456. 
  457. void
       ^
  458. ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
  459. {

src/http/modules/ngx_http_limit_req_module.c:604:9: Call
602.         ngx_rbtree_delete(&ctx->sh->rbtree, node);
603. 
604.         ngx_slab_free_locked(ctx->shpool, node);
             ^
605.     }
606. }

src/core/ngx_slab.c:457:1: <LHS trace>
455. 
456. 
457. void
     ^
458. ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
459. {

src/core/ngx_slab.c:457:1: Parameter `pool->stats->total`
  455. 
  456. 
  457. void
       ^
  458. ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
  459. {

src/core/ngx_slab.c:570:13: Binary operation: ([0, +oo] - 64):unsigned64 by call to `ngx_slab_free_locked` 
  568.             ngx_slab_free_pages(pool, page, 1);
  569. 
  570.             pool->stats[slot].total -= 8 * sizeof(uintptr_t);
                   ^
  571. 
  572.             goto done;
