| Message ID | 938a827f9927ee2112d98e2053ad7764aae9d8f8.1638308023.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS | expand |
On Tue, Nov 30, 2021 at 10:41 PM <andrey.konovalov@linux.dev> wrote: > > From: Andrey Konovalov <andreyknvl@google.com> > > __GFP_ZEROTAGS should only be effective if memory is being zeroed. > Currently, hardware tag-based KASAN violates this requirement. > > Fix by including an initialization check along with checking for > __GFP_ZEROTAGS. > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> > --- > mm/kasan/hw_tags.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c > index 0b8225add2e4..c643740b8599 100644 > --- a/mm/kasan/hw_tags.c > +++ b/mm/kasan/hw_tags.c > @@ -199,11 +199,12 @@ void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags) > * page_alloc.c. > */ > bool init = !want_init_on_free() && want_init_on_alloc(flags); > + bool init_tags = init && (flags & __GFP_ZEROTAGS); > > if (flags & __GFP_SKIP_KASAN_POISON) > SetPageSkipKASanPoison(page); > > - if (flags & __GFP_ZEROTAGS) { > + if (init_tags) { > int i; > > for (i = 0; i != 1 << order; ++i) > -- > 2.25.1 >
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 0b8225add2e4..c643740b8599 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -199,11 +199,12 @@ void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags) * page_alloc.c. */ bool init = !want_init_on_free() && want_init_on_alloc(flags); + bool init_tags = init && (flags & __GFP_ZEROTAGS); if (flags & __GFP_SKIP_KASAN_POISON) SetPageSkipKASanPoison(page); - if (flags & __GFP_ZEROTAGS) { + if (init_tags) { int i; for (i = 0; i != 1 << order; ++i)