src/http/modules/ngx_http_limit_conn_module.c:413: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned64 by call to `ngx_slab_free_locked`.

src/http/modules/ngx_http_limit_conn_module.c:413:9: Call
411.     if (lc->conn == 0) {
412.         ngx_rbtree_delete(&ctx->sh->rbtree, node);
413.         ngx_slab_free_locked(ctx->shpool, node);
             ^
414.     }
415. 

src/core/ngx_slab.c:460:1: <LHS trace>
458. 
459. 
460. void
     ^
461. ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
462. {

src/core/ngx_slab.c:460:1: Global `ngx_pagesize`
  458. 
  459. 
  460. void
       ^
  461. ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
  462. {

src/core/ngx_slab.c:491:9: Binary operation: ([0, +oo] - 1):unsigned64 by call to `ngx_slab_free_locked` 
  489.         }
  490. 
  491.         n = ((uintptr_t) p & (ngx_pagesize - 1)) >> shift;
               ^
  492.         m = (uintptr_t) 1 << (n % (8 * sizeof(uintptr_t)));
  493.         n /= 8 * sizeof(uintptr_t);
