Hi Henry, On Mon, Jul 1, 2019 at 8:31 PM Henry Burns <henryburns@xxxxxxxxxx> wrote: > > Running z3fold stress testing with address sanitization > showed zhdr->slots was being used after it was freed. > > z3fold_free(z3fold_pool, handle) > free_handle(handle) > kmem_cache_free(pool->c_handle, zhdr->slots) > release_z3fold_page_locked_list(kref) > __release_z3fold_page(zhdr, true) > zhdr_to_pool(zhdr) > slots_to_pool(zhdr->slots) *BOOM* Thanks for looking into this. I'm not entirely sure I'm all for splitting free_handle() but let me think about it. > Instead we split free_handle into two functions, release_handle() > and free_slots(). We use release_handle() in place of free_handle(), > and use free_slots() to call kmem_cache_free() after > __release_z3fold_page() is done. A little less intrusive solution would be to move backlink to pool from slots back to z3fold_header. Looks like it was a bad idea from the start. Best regards, Vitaly
