src/core/ngx_slab.c:585: error: Integer Overflow L2
  ([0, `pool->pages->slab`] - 1):unsigned64 by call to `ngx_slab_free_pages`.

src/core/ngx_slab.c:412:1: Parameter `pool->pages->slab`
410. 
411. 
412. void
     ^
413. ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
414. {

src/core/ngx_slab.c:429:5: Assignment
427.     n = ((u_char *) p - pool->start) >> ngx_pagesize_shift;
428.     page = &pool->pages[n];
429.     slab = page->slab;
         ^
430.     type = page->prev & NGX_SLAB_PAGE_MASK;
431. 

src/core/ngx_slab.c:583:9: Assignment
581. 
582.         n = ((u_char *) p - pool->start) >> ngx_pagesize_shift;
583.         size = slab & ~NGX_SLAB_PAGE_START;
             ^
584. 
585.         ngx_slab_free_pages(pool, &pool->pages[n], size);

src/core/ngx_slab.c:585:9: Call
583.         size = slab & ~NGX_SLAB_PAGE_START;
584. 
585.         ngx_slab_free_pages(pool, &pool->pages[n], size);
             ^
586. 
587.         ngx_slab_junk(p, size << ngx_pagesize_shift);

src/core/ngx_slab.c:669:1: <LHS trace>
667. 
668. 
669. static void
     ^
670. ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page,
671.     ngx_uint_t pages)

src/core/ngx_slab.c:669:1: Parameter `pages`
  667. 
  668. 
  669. static void
       ^
  670. ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page,
  671.     ngx_uint_t pages)

src/core/ngx_slab.c:675:18: Binary operation: ([0, pool->pages->slab] - 1):unsigned64 by call to `ngx_slab_free_pages` 
  673.     ngx_slab_page_t  *prev;
  674. 
  675.     page->slab = pages--;
                        ^
  676. 
  677.     if (pages) {
