4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit bf7d28c53453ea904584960de55e33e03b9d93b1 ]
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 peng.hao2@zte.com.cn Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: Tom Lendacky thomas.lendacky@amd.com 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.co... Signed-off-by: Sasha Levin sashal@kernel.org --- 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 7ae36868aed25..c9faf34cbb62e 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -157,8 +157,8 @@ 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))); }