On Tue, Mar 20, 2018 at 1:44 AM, Anthony Yznaga
<anthony.yznaga@xxxxxxxxxx> wrote:
> Hi Andrey,
>
> On 3/2/18 11:44 AM, Andrey Konovalov wrote:
>> void kasan_poison_kfree(void *ptr, unsigned long ip)
>> {
>> + struct page *page;
>> +
>> + page = virt_to_head_page(ptr)
>
> An untagged addr should be passed to virt_to_head_page(), no?
Hi!
virt_to_head_page() relies on virt_to_phys(), and the latter will be
fixed to accept tagged pointers in the next patchset.
Thanks!
>
>> +
>> + if (unlikely(!PageSlab(page))) {
>> + if (reset_tag(ptr) != page_address(page)) {
>> + /* Report invalid-free here */
>> + return;
>> + }
>> + kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
>> + khwasan_random_tag());
>> + } else {
>> + __kasan_slab_free(page->slab_cache, ptr, ip);
>> + }
>> }
>>
>> void kasan_kfree_large(void *ptr, unsigned long ip)
>> {
>> + struct page *page = virt_to_page(ptr);
>> + struct page *head_page = virt_to_head_page(ptr);
>
> Same as above and for virt_to_page() as well.
>
> Anthony
>
>
>> +
>> + if (reset_tag(ptr) != page_address(head_page)) {
>> + /* Report invalid-free here */
>> + return;
>> + }
>> +
>> + kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
>> + khwasan_random_tag());
>> }
