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[209.132.180.67]) by mx.google.com with ESMTP id c22si454803oic.108.2020.03.07.02.10.20; Sat, 07 Mar 2020 02:10:32 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@c-s.fr header.s=mail header.b=VA8mEknU; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726239AbgCGKJY (ORCPT + 99 others); Sat, 7 Mar 2020 05:09:24 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:29426 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725878AbgCGKJX (ORCPT ); Sat, 7 Mar 2020 05:09:23 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 48ZKw04l91z9tyJV; Sat, 7 Mar 2020 11:09:20 +0100 (CET) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=VA8mEknU; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 32DtUaR_qY3G; Sat, 7 Mar 2020 11:09:20 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 48ZKw03V1zz9tyJT; Sat, 7 Mar 2020 11:09:20 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1583575760; bh=QF5moGMgYbnR8ZU8yFqiJqUSMgosscuIMeqnvY3R3MA=; h=From:Subject:To:Cc:Date:From; b=VA8mEknU+jpXH6BiQrTOc8wox0jcH31NzFYTXDaCnZ6ny3nweAZS6E6S6D/N3zmBy M9A9AWT58xSzxji9J7FKFCk/K2cDJnXJvkJsqCdubq+yK7erUZDPHnW4j5iCEL6sgI r474TiPxz9rPb5IxEtFxAUaR2OYx9DePZg+UfEfY= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 995CC8B785; Sat, 7 Mar 2020 11:09:16 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id DwWifxh8Ip9Y; Sat, 7 Mar 2020 11:09:16 +0100 (CET) Received: from pc16570vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 5CD438B776; Sat, 7 Mar 2020 11:09:16 +0100 (CET) Received: by pc16570vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 1682365494; Sat, 7 Mar 2020 10:09:15 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH] powerpc/32: Fix missing NULL pmd check in virt_to_kpte() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , ndesaulniers@google.com Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Sat, 7 Mar 2020 10:09:15 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 2efc7c085f05 ("powerpc/32: drop get_pteptr()"), replaced get_pteptr() by virt_to_kpte(). But virt_to_kpte() lacks a NULL pmd check and returns an invalid non NULL pointer when there is no page table. Reported-by: Nick Desaulniers Fixes: 2efc7c085f05 ("powerpc/32: drop get_pteptr()") Signed-off-by: Christophe Leroy --- arch/powerpc/include/asm/pgtable.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index b80bfd41828d..b1f1d5339735 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -54,7 +54,9 @@ static inline pmd_t *pmd_ptr_k(unsigned long va) static inline pte_t *virt_to_kpte(unsigned long vaddr) { - return pte_offset_kernel(pmd_ptr_k(vaddr), vaddr); + pmd_t *pmd = pmd_ptr_k(vaddr); + + return pmd_none(*pmd) ? NULL : pte_offset_kernel(pmd, vaddr); } #endif -- 2.25.0