diff options
author | Andrey Konovalov <andreyknvl@google.com> | 2023-12-20 01:28:56 +0300 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-29 22:58:39 +0300 |
commit | 29d7355a9d05de9a6e38cc4d1146fb96c43853fb (patch) | |
tree | 298b492f9270c8fadd84f13c49a23174572c51fe | |
parent | 0cc9fdbf4a5273310779bd4779fcdfb4705438a6 (diff) | |
download | linux-29d7355a9d05de9a6e38cc4d1146fb96c43853fb.tar.xz |
kasan: save alloc stack traces for mempool
Update kasan_mempool_unpoison_object to properly poison the redzone and
save alloc strack traces for kmalloc and slab pools.
As a part of this change, split out and use a unpoison_slab_object helper
function from __kasan_slab_alloc.
[nathan@kernel.org: mark unpoison_slab_object() as static]
Link: https://lkml.kernel.org/r/20231221180042.104694-1-andrey.konovalov@linux.dev
Link: https://lkml.kernel.org/r/05ad235da8347cfe14d496d01b2aaf074b4f607c.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | include/linux/kasan.h | 7 | ||||
-rw-r--r-- | mm/kasan/common.c | 50 |
2 files changed, 44 insertions, 13 deletions
diff --git a/include/linux/kasan.h b/include/linux/kasan.h index e636a00e26ba..7392c5d89b92 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -303,9 +303,10 @@ void __kasan_mempool_unpoison_object(void *ptr, size_t size, unsigned long ip); * mempool). * * This function unpoisons a slab allocation that was previously poisoned via - * kasan_mempool_poison_object() without initializing its memory. For the - * tag-based modes, this function does not assign a new tag to the allocation - * and instead restores the original tags based on the pointer value. + * kasan_mempool_poison_object() and saves an alloc stack trace for it without + * initializing the allocation's memory. For the tag-based modes, this function + * does not assign a new tag to the allocation and instead restores the + * original tags based on the pointer value. * * This function operates on all slab allocations including large kmalloc * allocations (the ones returned by kmalloc_large() or by kmalloc() with the diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 962805bf5f62..bf16c2dfa8e7 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -277,6 +277,20 @@ void __kasan_kfree_large(void *ptr, unsigned long ip) /* The object will be poisoned by kasan_poison_pages(). */ } +static inline void unpoison_slab_object(struct kmem_cache *cache, void *object, + gfp_t flags, bool init) +{ + /* + * Unpoison the whole object. For kmalloc() allocations, + * poison_kmalloc_redzone() will do precise poisoning. + */ + kasan_unpoison(object, cache->object_size, init); + + /* Save alloc info (if possible) for non-kmalloc() allocations. */ + if (kasan_stack_collection_enabled() && !is_kmalloc_cache(cache)) + kasan_save_alloc_info(cache, object, flags); +} + void * __must_check __kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags, bool init) { @@ -299,15 +313,8 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache, tag = assign_tag(cache, object, false); tagged_object = set_tag(object, tag); - /* - * Unpoison the whole object. - * For kmalloc() allocations, kasan_kmalloc() will do precise poisoning. - */ - kasan_unpoison(tagged_object, cache->object_size, init); - - /* Save alloc info (if possible) for non-kmalloc() allocations. */ - if (kasan_stack_collection_enabled() && !is_kmalloc_cache(cache)) - kasan_save_alloc_info(cache, tagged_object, flags); + /* Unpoison the object and save alloc info for non-kmalloc() allocations. */ + unpoison_slab_object(cache, tagged_object, flags, init); return tagged_object; } @@ -482,7 +489,30 @@ bool __kasan_mempool_poison_object(void *ptr, unsigned long ip) void __kasan_mempool_unpoison_object(void *ptr, size_t size, unsigned long ip) { - kasan_unpoison(ptr, size, false); + struct slab *slab; + gfp_t flags = 0; /* Might be executing under a lock. */ + + if (is_kfence_address(kasan_reset_tag(ptr))) + return; + + slab = virt_to_slab(ptr); + + /* + * This function can be called for large kmalloc allocation that get + * their memory from page_alloc. + */ + if (unlikely(!slab)) { + kasan_unpoison(ptr, size, false); + poison_kmalloc_large_redzone(ptr, size, flags); + return; + } + + /* Unpoison the object and save alloc info for non-kmalloc() allocations. */ + unpoison_slab_object(slab->slab_cache, ptr, size, flags); + + /* Poison the redzone and save alloc info for kmalloc() allocations. */ + if (is_kmalloc_cache(slab->slab_cache)) + poison_kmalloc_redzone(slab->slab_cache, ptr, size, flags); } bool __kasan_check_byte(const void *address, unsigned long ip) |