src/http/modules/ngx_http_limit_req_module.c:247: error: Integer Overflow L1
  (0 - 1):unsigned64.

src/http/modules/ngx_http_limit_req_module.c:251:13: <LHS trace>
249.             ngx_shmtx_unlock(&ctx->shpool->mutex);
250. 
251.             ctx->node = NULL;
                 ^
252.         }
253. 

src/http/modules/ngx_http_limit_req_module.c:251:13: Assignment
249.             ngx_shmtx_unlock(&ctx->shpool->mutex);
250. 
251.             ctx->node = NULL;
                 ^
252.         }
253. 

src/http/modules/ngx_http_limit_req_module.c:245:13: Call
243.             }
244. 
245.             ngx_shmtx_lock(&ctx->shpool->mutex);
                 ^
246. 
247.             ctx->node->count--;

src/core/ngx_shmtx.c:69:1: Parameter `mtx->spin`
  67. 
  68. 
  69. void
      ^
  70. ngx_shmtx_lock(ngx_shmtx_t *mtx)
  71. {

src/http/modules/ngx_http_limit_req_module.c:247:13: Binary operation: (0 - 1):unsigned64
245.             ngx_shmtx_lock(&ctx->shpool->mutex);
246. 
247.             ctx->node->count--;
                 ^
248. 
249.             ngx_shmtx_unlock(&ctx->shpool->mutex);
