From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43FF9C433E0 for ; Tue, 29 Dec 2020 20:53:53 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4892820771 for ; Tue, 29 Dec 2020 20:53:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4892820771 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=126.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4D568Y49ybzDqFw for ; Wed, 30 Dec 2020 07:53:49 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=126.com (client-ip=220.181.15.112; helo=m15112.mail.126.com; envelope-from=bodefang@126.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=126.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=126.com header.i=@126.com header.a=rsa-sha256 header.s=s110527 header.b=NtHzNaDk; dkim-atps=neutral X-Greylist: delayed 1996 seconds by postgrey-1.36 at bilbo; Mon, 28 Dec 2020 14:49:20 AEDT Received: from m15112.mail.126.com (m15112.mail.126.com [220.181.15.112]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4D43Sw5KjTzDqBZ for ; Mon, 28 Dec 2020 14:49:18 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=From:Subject:Date:Message-Id; bh=rHDg0EM4Tc1M0YYKA4 UQMqhy0tOgpr+WAMZImhXGOPI=; b=NtHzNaDkdtCeFRfNcfqGRqx3IgKH9zeS3l zRMSm+9FOhhQQIRYnVg5N+i4zKgyO+xHQzDpUNz6BgLZiz1E6+g61pfOlE77N1cy IJQrmGDlqv0DpVj0WAgcWHpOu8BdKAn41HLj/ib6zornorzyZe62JqEpF39pjKdD DqehwFycY= Received: from localhost.localdomain (unknown [36.112.86.14]) by smtp2 (Coremail) with SMTP id DMmowAAX3UDBTOlf7uVwKg--.26924S2; Mon, 28 Dec 2020 11:10:58 +0800 (CST) From: Defang Bo To: mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, christophe.leroy@csgroup.eu, akpm@linux-foundation.org, geert@linux-m68k.org, rppt@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH] powerpc/mm: add sanity check to avoid null pointer dereference Date: Mon, 28 Dec 2020 11:10:50 +0800 Message-Id: <1609125050-240351-1-git-send-email-bodefang@126.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: DMmowAAX3UDBTOlf7uVwKg--.26924S2 X-Coremail-Antispam: 1Uf129KBjvJXoWrZFW3Cw4xCF17Wr4xuFW3Jrb_yoW8JF4rpw 1vyr1vvw4Fq3Z5KrySkF1DWryYga1ktF1xC39Fk398ua4rtws5uF1fKwnYya13XF95C3WS kFZxKw15Jr13X37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zRX_-QUUUUU= X-Originating-IP: [36.112.86.14] X-CM-SenderInfo: pergvwxdqjqiyswou0bp/1tbiFgwJ11pECtLJ6gAAsh X-Mailman-Approved-At: Wed, 30 Dec 2020 07:50:45 +1100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Defang Bo Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Similar to commit<0dc294f717d4>("powerpc/mm: bail out early when flushing TLB page"), there should be a check for 'mm' to prevent Null pointer dereference in case of 'mm' argument was legitimately passed. Signed-off-by: Defang Bo --- arch/powerpc/mm/nohash/tlb.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c index 5872f69..1d89335 100644 --- a/arch/powerpc/mm/nohash/tlb.c +++ b/arch/powerpc/mm/nohash/tlb.c @@ -192,6 +192,9 @@ void local_flush_tlb_mm(struct mm_struct *mm) { unsigned int pid; + if (WARN_ON(!mm)) + return; + preempt_disable(); pid = mm->context.id; if (pid != MMU_NO_CONTEXT) @@ -205,8 +208,11 @@ void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr, { unsigned int pid; + if (WARN_ON(!mm)) + return; + preempt_disable(); - pid = mm ? mm->context.id : 0; + pid = mm->context.id; if (pid != MMU_NO_CONTEXT) _tlbil_va(vmaddr, pid, tsize, ind); preempt_enable(); @@ -268,6 +274,9 @@ void flush_tlb_mm(struct mm_struct *mm) { unsigned int pid; + if (WARN_ON(!mm)) + return; + preempt_disable(); pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) -- 2.7.4