From f129c31039283df884913142b0f3797d64d3a9d6 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 19 Dec 2023 23:28:50 +0100 Subject: kasan: introduce kasan_mempool_poison_pages Introduce and document a kasan_mempool_poison_pages hook to be used by the mempool code instead of kasan_poison_pages. Compated to kasan_poison_pages, the new hook: 1. For the tag-based modes, skips checking and poisoning allocations that were not tagged due to sampling. 2. Checks for double-free and invalid-free bugs. In the future, kasan_poison_pages can also be updated to handle #2, but this is out-of-scope of this series. Link: https://lkml.kernel.org/r/88dc7340cce28249abf789f6e0c792c317df9ba5.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Lobakin Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Breno Leitao Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Marco Elver Signed-off-by: Andrew Morton --- include/linux/kasan.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/linux/kasan.h') diff --git a/include/linux/kasan.h b/include/linux/kasan.h index c5fe303bc1c2..de2a695ad34d 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -212,6 +212,29 @@ static __always_inline void * __must_check kasan_krealloc(const void *object, return (void *)object; } +bool __kasan_mempool_poison_pages(struct page *page, unsigned int order, + unsigned long ip); +/** + * kasan_mempool_poison_pages - Check and poison a mempool page allocation. + * @page: Pointer to the page allocation. + * @order: Order of the allocation. + * + * This function is intended for kernel subsystems that cache page allocations + * to reuse them instead of freeing them back to page_alloc (e.g. mempool). + * + * This function is similar to kasan_mempool_poison_object() but operates on + * page allocations. + * + * Return: true if the allocation can be safely reused; false otherwise. + */ +static __always_inline bool kasan_mempool_poison_pages(struct page *page, + unsigned int order) +{ + if (kasan_enabled()) + return __kasan_mempool_poison_pages(page, order, _RET_IP_); + return true; +} + bool __kasan_mempool_poison_object(void *ptr, unsigned long ip); /** * kasan_mempool_poison_object - Check and poison a mempool slab allocation. @@ -326,6 +349,10 @@ static inline void *kasan_krealloc(const void *object, size_t new_size, { return (void *)object; } +static inline bool kasan_mempool_poison_pages(struct page *page, unsigned int order) +{ + return true; +} static inline bool kasan_mempool_poison_object(void *ptr) { return true; -- cgit v1.2.3