kasan: ensure poisoning size alignment

[linux-2.6-microblaze.git] / mm / kasan / shadow.c

diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index 1ed7817..63f4344 100644 (file)
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -69,7 +69,7 @@ void *memcpy(void *dest, const void *src, size_t len)
        return __memcpy(dest, src, len);
 }
 
-void kasan_poison(const void *address, size_t size, u8 value)
+void kasan_poison(const void *addr, size_t size, u8 value)
 {
        void *shadow_start, *shadow_end;
 
@@ -78,55 +78,62 @@ void kasan_poison(const void *address, size_t size, u8 value)
         * some of the callers (e.g. kasan_poison_object_data) pass tagged
         * addresses to this function.
         */
-       address = kasan_reset_tag(address);
+       addr = kasan_reset_tag(addr);
 
        /* Skip KFENCE memory if called explicitly outside of sl*b. */
-       if (is_kfence_address(address))
+       if (is_kfence_address(addr))
                return;
 
-       size = round_up(size, KASAN_GRANULE_SIZE);
-       shadow_start = kasan_mem_to_shadow(address);
-       shadow_end = kasan_mem_to_shadow(address + size);
+       if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
+               return;
+       if (WARN_ON(size & KASAN_GRANULE_MASK))
+               return;
+
+       shadow_start = kasan_mem_to_shadow(addr);
+       shadow_end = kasan_mem_to_shadow(addr + size);
 
        __memset(shadow_start, value, shadow_end - shadow_start);
 }
 EXPORT_SYMBOL(kasan_poison);
 
 #ifdef CONFIG_KASAN_GENERIC
-void kasan_poison_last_granule(const void *address, size_t size)
+void kasan_poison_last_granule(const void *addr, size_t size)
 {
        if (size & KASAN_GRANULE_MASK) {
-               u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
+               u8 *shadow = (u8 *)kasan_mem_to_shadow(addr + size);
                *shadow = size & KASAN_GRANULE_MASK;
        }
 }
 #endif
 
-void kasan_unpoison(const void *address, size_t size)
+void kasan_unpoison(const void *addr, size_t size)
 {
-       u8 tag = get_tag(address);
+       u8 tag = get_tag(addr);
 
        /*
         * Perform shadow offset calculation based on untagged address, as
         * some of the callers (e.g. kasan_unpoison_object_data) pass tagged
         * addresses to this function.
         */
-       address = kasan_reset_tag(address);
+       addr = kasan_reset_tag(addr);
 
        /*
         * Skip KFENCE memory if called explicitly outside of sl*b. Also note
         * that calls to ksize(), where size is not a multiple of machine-word
         * size, would otherwise poison the invalid portion of the word.
         */
-       if (is_kfence_address(address))
+       if (is_kfence_address(addr))
+               return;
+
+       if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
                return;
 
-       /* Unpoison round_up(size, KASAN_GRANULE_SIZE) bytes. */
-       kasan_poison(address, size, tag);
+       /* Unpoison all granules that cover the object. */
+       kasan_poison(addr, round_up(size, KASAN_GRANULE_SIZE), tag);
 
        /* Partially poison the last granule for the generic mode. */
        if (IS_ENABLED(CONFIG_KASAN_GENERIC))
-               kasan_poison_last_granule(address, size);
+               kasan_poison_last_granule(addr, size);
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG