From bf7d28c53453ea904584960de55e33e03b9d93b1 Mon Sep 17 00:00:00 2001 From: Peng Hao Date: Sat, 29 Dec 2018 14:34:12 +0800 Subject: [PATCH] x86/mm/mem_encrypt: Fix erroneous sizeof() Using sizeof(pointer) for determining the size of a memset() only works when the size of the pointer and the size of type to which it points are the same. For pte_t this is only true for 64bit and 32bit-NONPAE. On 32bit PAE systems this is wrong as the pointer size is 4 byte but the PTE entry is 8 bytes. It's actually not a real world issue as this code depends on 64bit, but it's wrong nevertheless. Use sizeof(*p) for correctness sake. Fixes: aad983913d77 ("x86/mm/encrypt: Simplify sme_populate_pgd() and sme_populate_pgd_large()") Signed-off-by: Peng Hao Signed-off-by: Thomas Gleixner Cc: Kirill A. Shutemov Cc: Tom Lendacky Cc: dave.hansen@linux.intel.com Cc: peterz@infradead.org Cc: luto@kernel.org Link: https://lkml.kernel.org/r/1546065252-97996-1-git-send-email-peng.hao2@zte.com.cn --- arch/x86/mm/mem_encrypt_identity.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index a19ef1a416ff..4aa9b1480866 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -158,8 +158,8 @@ static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd) pmd = pmd_offset(pud, ppd->vaddr); if (pmd_none(*pmd)) { pte = ppd->pgtable_area; - memset(pte, 0, sizeof(pte) * PTRS_PER_PTE); - ppd->pgtable_area += sizeof(pte) * PTRS_PER_PTE; + memset(pte, 0, sizeof(*pte) * PTRS_PER_PTE); + ppd->pgtable_area += sizeof(*pte) * PTRS_PER_PTE; set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte))); } -- 2.30.2