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| author | Andrey Konovalov <andreyknvl@google.com> | 2022-03-24 18:10:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-24 19:06:46 -0700 |
| commit | 1c0e5b24f11707e8c8300060bfdd9ae4ae76611b (patch) | |
| tree | 8110648a41187049c33d00a72c62714a85e8eae3 | |
| parent | c82ce3195fd17e57a370e4dc8f36c195b8807b95 (diff) | |
| download | linux-1c0e5b24f11707e8c8300060bfdd9ae4ae76611b.tar.gz | |
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@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/kasan/hw_tags.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 0b8225add2e489..c643740b859969 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) |