From patchwork Wed Dec 22 01:12:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Peng X-Patchwork-Id: 12690793 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B927C433F5 for ; Wed, 22 Dec 2021 01:13:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238381AbhLVBNL (ORCPT ); Tue, 21 Dec 2021 20:13:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230433AbhLVBNK (ORCPT ); Tue, 21 Dec 2021 20:13:10 -0500 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AA76C061574; Tue, 21 Dec 2021 17:13:10 -0800 (PST) Received: by mail-pf1-x434.google.com with SMTP id t123so794329pfc.13; Tue, 21 Dec 2021 17:13:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=3tuVnOiMraCwH10Uv8N7IHwNP9xedfBBpuE0UrBCKDE=; b=h/WakJ+6ykw780HcE+D18jLdSMBGs+iwIV8UIO16Fn5/S/P0gPx6DbBlgEpmm8YNDg IWtCFPEheqU/z5I2Cpm2dM+O3s3qfzdORm5xX9PHRQQOKdMKZyJw+vuvI7DJ4eTFRrSs NIr4TRqlbnu426cCSrrWy3n/0z9ue8vDADrmOww+ouU74vlOjhv6bErPoVceeRxXlm7Y xDw2VWS+frEA32pom/LAykXe/kDs/nfillUNTtIHmjH4UyFgH3cbeX7zwaDQzjYRSLoZ rOsF5E3l30xxp97/eMvoKrqfMlvNQ3727uKKHFh8UcuGlW2ajT+N8GR4kp0BOlXNzF74 nJyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=3tuVnOiMraCwH10Uv8N7IHwNP9xedfBBpuE0UrBCKDE=; b=LsbH3Vn/KFHA0ZAMM1Pz49c/q8hW21z5OUqCIuL/6aDIDNYlMPtPA9w14axNMgxAv6 IXQuAuRJETc+tTrCvX6LbTqZgmfNaA+5FIGhIILMinK2HAIEeLTBmEtuYao2EdIwGKlX Poo12m3Xij5jCJX3ydZic+vrzgsZiipDkayckL5y3+0OWz0w2HThwuthvCtozHNZaRqx y/WsLEyKV90a9+bnUYMkJuCGKx4KMV9DBDyRmvFZICGKv70AQyljU9ELCyUX0WRN+2P7 yVRcIB99KBej5QqeiPpbqgEJZJPf8V3NEyv5EHh2qPFwVajhEDdpeMOwk4eBvatwbeVw dm6g== X-Gm-Message-State: AOAM530AptH4HBU7SKYmxYIqFeW9UZXTA00+nqbkpGJoPs/27bevD71T sPyPXDnjl5zdEVhHUJnXtiA= X-Google-Smtp-Source: ABdhPJyzsmoQ/NTUp3e/vm0A72wJblWVESub0GoYMNPwEVywO0vEzAKA43tppPZZ2Y5yZR2hRIh2nQ== X-Received: by 2002:aa7:8153:0:b0:4a8:2c13:dab7 with SMTP id d19-20020aa78153000000b004a82c13dab7mr645957pfn.51.1640135590127; Tue, 21 Dec 2021 17:13:10 -0800 (PST) Received: from FLYINGPENG-MB0.tencent.com ([103.7.29.30]) by smtp.gmail.com with ESMTPSA id np1sm4015315pjb.22.2021.12.21.17.13.07 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Dec 2021 17:13:09 -0800 (PST) From: Peng Hao X-Google-Original-From: Peng Hao To: david@redhat.com, mst@redhat.com Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] virtio/virtio_mem: handle a possible NULL as a memcpy parameter Date: Wed, 22 Dec 2021 09:12:25 +0800 Message-Id: <20211222011225.40573-1-flyingpeng@tencent.com> X-Mailer: git-send-email 2.30.1 (Apple Git-130) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org There is a check for vm->sbm.sb_states before, and it should check it here as well. Signed-off-by: Peng Hao --- drivers/virtio/virtio_mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 96e5a8782769..b6b7c489c8b6 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -592,7 +592,7 @@ static int virtio_mem_sbm_sb_states_prepare_next_mb(struct virtio_mem *vm) return -ENOMEM; mutex_lock(&vm->hotplug_mutex); - if (new_bitmap) + if (vm->sbm.sb_states) memcpy(new_bitmap, vm->sbm.sb_states, old_pages * PAGE_SIZE); old_bitmap = vm->sbm.sb_states;