Messages in this thread Patch in this message | | | From | Andrey Konovalov <> | Subject | [PATCH v10 12/22] kasan, arm64: fix up fault handling logic | Date | Tue, 6 Nov 2018 18:30:27 +0100 |
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show_pte in arm64 fault handling relies on the fact that the top byte of a kernel pointer is 0xff, which isn't always the case with tag-based KASAN.
This patch resets the top byte in show_pte.
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- arch/arm64/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 7d9571f4ae3d..d9a84d6f3343 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -32,6 +32,7 @@ #include <linux/perf_event.h> #include <linux/preempt.h> #include <linux/hugetlb.h> +#include <linux/kasan.h> #include <asm/bug.h> #include <asm/cmpxchg.h> @@ -141,6 +142,8 @@ void show_pte(unsigned long addr) pgd_t *pgdp; pgd_t pgd; + addr = (unsigned long)kasan_reset_tag((void *)addr); + if (addr < TASK_SIZE) { /* TTBR0 */ mm = current->active_mm; -- 2.19.1.930.g4563a0d9d0-goog
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