The patch titled
Subject: kasan: only apply __GFP_ZEROTAGS when memory is zeroed
has been removed from the -mm tree. Its filename was
kasan-only-apply-__gfp_zerotags-when-memory-is-zeroed.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: only apply __GFP_ZEROTAGS when memory is zeroed
__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.
Link: https://lkml.kernel.org/r/f4f4593f7f675262d29d07c1938db5bd0cd5e285.1643047180.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>
Acked-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/hw_tags.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/kasan/hw_tags.c~kasan-only-apply-__gfp_zerotags-when-memory-is-zeroed
+++ a/mm/kasan/hw_tags.c
@@ -199,11 +199,12 @@ void kasan_alloc_pages(struct page *page
* 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)
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
stacktrace-add-interface-based-on-shadow-call-stack.patch
arm64-scs-save-scs_sp-values-per-cpu-when-switching-stacks.patch
arm64-implement-stack_trace_save_shadow.patch
kasan-use-stack_trace_save_shadow.patch
