Re: [PATCH mm 00/21] kasan: save mempool stack traces

[Marco Elver <elver@google.com>]

On Tue, 19 Dec 2023 at 23:29, <andrey.konovalov@linux.dev> wrote:
>
> From: Andrey Konovalov <andreyknvl@google.com>
>
> This series updates KASAN to save alloc and free stack traces for
> secondary-level allocators that cache and reuse allocations internally
> instead of giving them back to the underlying allocator (e.g. mempool).
>
> As a part of this change, introduce and document a set of KASAN hooks:
>
> bool kasan_mempool_poison_pages(struct page *page, unsigned int order);
> void kasan_mempool_unpoison_pages(struct page *page, unsigned int order);
> bool kasan_mempool_poison_object(void *ptr);
> void kasan_mempool_unpoison_object(void *ptr, size_t size);
>
> and use them in the mempool code.
>
> Besides mempool, skbuff and io_uring also cache allocations and already
> use KASAN hooks to poison those. Their code is updated to use the new
> mempool hooks.
>
> The new hooks save alloc and free stack traces (for normal kmalloc and
> slab objects; stack traces for large kmalloc objects and page_alloc are
> not supported by KASAN yet), improve the readability of the users' code,
> and also allow the users to prevent double-free and invalid-free bugs;
> see the patches for the details.
>
> There doesn't appear to be any conflicts with the KASAN patches that are
> currently in mm, but I rebased the patchset on top just in case.
>
> Changes RFC->v1:
> - New patch "mempool: skip slub_debug poisoning when KASAN is enabled".
> - Replace mempool_use_prealloc_only API with mempool_alloc_preallocated.
> - Avoid triggering slub_debug-detected corruptions in mempool tests.
>
> Andrey Konovalov (21):
>   kasan: rename kasan_slab_free_mempool to kasan_mempool_poison_object
>   kasan: move kasan_mempool_poison_object
>   kasan: document kasan_mempool_poison_object
>   kasan: add return value for kasan_mempool_poison_object
>   kasan: introduce kasan_mempool_unpoison_object
>   kasan: introduce kasan_mempool_poison_pages
>   kasan: introduce kasan_mempool_unpoison_pages
>   kasan: clean up __kasan_mempool_poison_object
>   kasan: save free stack traces for slab mempools
>   kasan: clean up and rename ____kasan_kmalloc
>   kasan: introduce poison_kmalloc_large_redzone
>   kasan: save alloc stack traces for mempool
>   mempool: skip slub_debug poisoning when KASAN is enabled
>   mempool: use new mempool KASAN hooks
>   mempool: introduce mempool_use_prealloc_only
>   kasan: add mempool tests
>   kasan: rename pagealloc tests
>   kasan: reorder tests
>   kasan: rename and document kasan_(un)poison_object_data
>   skbuff: use mempool KASAN hooks
>   io_uring: use mempool KASAN hook
>
>  include/linux/kasan.h   | 161 +++++++-
>  include/linux/mempool.h |   1 +
>  io_uring/alloc_cache.h  |   5 +-
>  mm/kasan/common.c       | 221 ++++++----
>  mm/kasan/kasan_test.c   | 870 +++++++++++++++++++++++++++-------------
>  mm/mempool.c            |  67 +++-
>  mm/slab.c               |  10 +-
>  mm/slub.c               |   4 +-
>  net/core/skbuff.c       |  10 +-
>  9 files changed, 954 insertions(+), 395 deletions(-)

Acked-by: Marco Elver <elver@google.com>