kasan: introduce poison_kmalloc_large_redzone

Split out a poison_kmalloc_large_redzone helper from __kasan_kmalloc_large
and use it in the caller's code.

This is a preparatory change for the following patches in this series.

Link: https://lkml.kernel.org/r/93317097b668519d76097fb065201b2027436e22.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
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 23:28:55 +01:00 committed by Andrew Morton
parent ce37eec0ab
commit 0cc9fdbf4a
1 changed files with 23 additions and 18 deletions

View File

@ -363,23 +363,12 @@ void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *object
}
EXPORT_SYMBOL(__kasan_kmalloc);
void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
static inline void poison_kmalloc_large_redzone(const void *ptr, size_t size,
gfp_t flags)
{
unsigned long redzone_start;
unsigned long redzone_end;
if (gfpflags_allow_blocking(flags))
kasan_quarantine_reduce();
if (unlikely(ptr == NULL))
return NULL;
/*
* The object has already been unpoisoned by kasan_unpoison_pages() for
* alloc_pages() or by kasan_krealloc() for krealloc().
*/
/*
* The redzone has byte-level precision for the generic mode.
* Partially poison the last object granule to cover the unaligned
@ -389,12 +378,25 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
kasan_poison_last_granule(ptr, size);
/* Poison the aligned part of the redzone. */
redzone_start = round_up((unsigned long)(ptr + size),
KASAN_GRANULE_SIZE);
redzone_start = round_up((unsigned long)(ptr + size), KASAN_GRANULE_SIZE);
redzone_end = (unsigned long)ptr + page_size(virt_to_page(ptr));
kasan_poison((void *)redzone_start, redzone_end - redzone_start,
KASAN_PAGE_REDZONE, false);
}
void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
gfp_t flags)
{
if (gfpflags_allow_blocking(flags))
kasan_quarantine_reduce();
if (unlikely(ptr == NULL))
return NULL;
/* The object has already been unpoisoned by kasan_unpoison_pages(). */
poison_kmalloc_large_redzone(ptr, size, flags);
/* Keep the tag that was set by alloc_pages(). */
return (void *)ptr;
}
@ -402,6 +404,9 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag
{
struct slab *slab;
if (gfpflags_allow_blocking(flags))
kasan_quarantine_reduce();
if (unlikely(object == ZERO_SIZE_PTR))
return (void *)object;
@ -419,11 +424,11 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag
/* Piggy-back on kmalloc() instrumentation to poison the redzone. */
if (unlikely(!slab))
return __kasan_kmalloc_large(object, size, flags);
else {
poison_kmalloc_large_redzone(object, size, flags);
else
poison_kmalloc_redzone(slab->slab_cache, object, size, flags);
return (void *)object;
}
return (void *)object;
}
bool __kasan_mempool_poison_pages(struct page *page, unsigned int order,