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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0588BC433EF for ; Mon, 24 Jan 2022 20:38:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386978AbiAXUgM (ORCPT ); Mon, 24 Jan 2022 15:36:12 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:37336 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346307AbiAXUNC (ORCPT ); Mon, 24 Jan 2022 15:13:02 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8465E6090A; Mon, 24 Jan 2022 20:13:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51E94C340E5; Mon, 24 Jan 2022 20:13:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643055180; bh=uwnNQ8+gL5Px1mLCB6XCmWKrCo2atGyRJwY5yIi3pNI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yOcWqydEh41D9gsjhpp7s/kylf/Mmbb9hh4fWSXVwKQK3swa4reJf97B/kB33IMU/ s96sIHCf3aLGIMuUa5gR2qG3eTghciHs0fKAZqgBgDWMwkCzPXuGtQSMiOE11+wDkE ZAUYEjBG/iLTM3pYnmVOkU3EolqnioRJgVMcu2nM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peng Hao , "Michael S. Tsirkin" Subject: [PATCH 5.15 067/846] virtio/virtio_mem: handle a possible NULL as a memcpy parameter Date: Mon, 24 Jan 2022 19:33:04 +0100 Message-Id: <20220124184103.280002812@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184100.867127425@linuxfoundation.org> References: <20220124184100.867127425@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peng Hao commit cf4a4493ff70874f8af26d75d4346c591c298e89 upstream. There is a check for vm->sbm.sb_states before, and it should check it here as well. Signed-off-by: Peng Hao Link: https://lore.kernel.org/r/20211222011225.40573-1-flyingpeng@tencent.com Signed-off-by: Michael S. Tsirkin Fixes: 5f1f79bbc9e2 ("virtio-mem: Paravirtualized memory hotplug") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Greg Kroah-Hartman --- drivers/virtio/virtio_mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -577,7 +577,7 @@ static int virtio_mem_sbm_sb_states_prep 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;