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| author | Andrey Konovalov <andreyknvl@google.com> | 2021-03-12 21:08:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-03-13 11:27:31 -0800 |
| commit | f9d79e8dce4077d3c6ab739c808169dfa99af9ef (patch) | |
| tree | 9e4ac9a440dec9b78161c28e976891317ea8203d /mm | |
| parent | 96cfe2c0fd23ea7c2368d14f769d287e7ae1082e (diff) | |
| download | lwn-f9d79e8dce4077d3c6ab739c808169dfa99af9ef.tar.gz lwn-f9d79e8dce4077d3c6ab739c808169dfa99af9ef.zip | |
kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC
Currently, kasan_free_nondeferred_pages()->kasan_free_pages() is called
after debug_pagealloc_unmap_pages(). This causes a crash when
debug_pagealloc is enabled, as HW_TAGS KASAN can't set tags on an
unmapped page.
This patch puts kasan_free_nondeferred_pages() before
debug_pagealloc_unmap_pages() and arch_free_page(), which can also make
the page unavailable.
Link: https://lkml.kernel.org/r/24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com
Fixes: 94ab5b61ee16 ("kasan, arm64: enable CONFIG_KASAN_HW_TAGS")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d4580e4215d8..3cd1c0ce4d06 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1282,6 +1282,12 @@ static __always_inline bool free_pages_prepare(struct page *page, kernel_poison_pages(page, 1 << order); /* + * With hardware tag-based KASAN, memory tags must be set before the + * page becomes unavailable via debug_pagealloc or arch_free_page. + */ + kasan_free_nondeferred_pages(page, order); + + /* * arch_free_page() can make the page's contents inaccessible. s390 * does this. So nothing which can access the page's contents should * happen after this. @@ -1290,8 +1296,6 @@ static __always_inline bool free_pages_prepare(struct page *page, debug_pagealloc_unmap_pages(page, 1 << order); - kasan_free_nondeferred_pages(page, order); - return true; } |