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authorAndrey Konovalov <andreyknvl@google.com>2021-02-25 17:20:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-26 09:41:03 -0800
commit200072ce33b298cf14d3ed2a570f5eb27609677d (patch)
treeb6abe3754df794b09701d737206c7b8be5b50e5a /mm/kasan/common.c
parentdf54b383124cf3e09f66644ee8a2eb977e8c7f26 (diff)
kasan: unify large kfree checks
Unify checks in kasan_kfree_large() and in kasan_slab_free_mempool() for large allocations as it's done for small kfree() allocations. With this change, kasan_slab_free_mempool() starts checking that the first byte of the memory that's being freed is accessible. Link: https://lkml.kernel.org/r/14ffc4cd867e0b1ed58f7527e3b748a1b4ad08aa.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/common.c')
-rw-r--r--mm/kasan/common.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 48d51daeda95..8a3d66393dc5 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -364,6 +364,31 @@ bool __kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
return ____kasan_slab_free(cache, object, ip, true);
}
+static bool ____kasan_kfree_large(void *ptr, unsigned long ip)
+{
+ if (ptr != page_address(virt_to_head_page(ptr))) {
+ kasan_report_invalid_free(ptr, ip);
+ return true;
+ }
+
+ if (!kasan_byte_accessible(ptr)) {
+ kasan_report_invalid_free(ptr, ip);
+ return true;
+ }
+
+ /*
+ * The object will be poisoned by kasan_free_pages() or
+ * kasan_slab_free_mempool().
+ */
+
+ return false;
+}
+
+void __kasan_kfree_large(void *ptr, unsigned long ip)
+{
+ ____kasan_kfree_large(ptr, ip);
+}
+
void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
{
struct page *page;
@@ -377,10 +402,8 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
* KMALLOC_MAX_SIZE, and kmalloc falls back onto page_alloc.
*/
if (unlikely(!PageSlab(page))) {
- if (ptr != page_address(page)) {
- kasan_report_invalid_free(ptr, ip);
+ if (____kasan_kfree_large(ptr, ip))
return;
- }
kasan_poison(ptr, page_size(page), KASAN_FREE_PAGE);
} else {
____kasan_slab_free(page->slab_cache, ptr, ip, false);
@@ -539,13 +562,6 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag
return ____kasan_kmalloc(page->slab_cache, object, size, flags);
}
-void __kasan_kfree_large(void *ptr, unsigned long ip)
-{
- if (ptr != page_address(virt_to_head_page(ptr)))
- kasan_report_invalid_free(ptr, ip);
- /* The object will be poisoned by kasan_free_pages(). */
-}
-
bool __kasan_check_byte(const void *address, unsigned long ip)
{
if (!kasan_byte_accessible(address)) {