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kasan: save alloc stack traces for mempool

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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>
This commit is contained in:
Andrey Konovalov 2023-12-19 23:28:56 +01:00 committed by Andrew Morton
parent 0cc9fdbf4a
commit 29d7355a9d
2 changed files with 44 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/kasan.h
View File

@ -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

48
mm/kasan/common.c
View File

@ -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)
{
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)