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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 163E9E9A768 for ; Tue, 24 Mar 2026 10:53:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1w4zOL-0007k5-Np; Tue, 24 Mar 2026 06:53:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w4zOJ-0007jY-V4 for qemu-devel@nongnu.org; Tue, 24 Mar 2026 06:53:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w4zOI-0000xc-78 for qemu-devel@nongnu.org; Tue, 24 Mar 2026 06:53:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774349620; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3YpUc/ODFStNWhZjRClnuP5z+oh++RSb6zDXm+hVTDc=; b=i6BqKXiBsnghTSZtDStoIdcYWGl1ms8cNibpbsizBlYXmmQ7PufiPlwYJp3SgpC101SBMP uZdWtzKCe8cezadncqNOychcIwmrWgAU2ApR6Xn4CuGev+q7BKFQl2SVaOaG0/0rDOjP5i kkDWw3wBQ1MStbD+SerUWrxV9zneYmU= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-407-jpi2PWFlMpahZlfDlh4vmg-1; Tue, 24 Mar 2026 06:53:39 -0400 X-MC-Unique: jpi2PWFlMpahZlfDlh4vmg-1 X-Mimecast-MFC-AGG-ID: jpi2PWFlMpahZlfDlh4vmg_1774349618 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 79C8D1956089; Tue, 24 Mar 2026 10:53:38 +0000 (UTC) Received: from redhat.com (unknown [10.44.33.93]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A8F3B180058C; Tue, 24 Mar 2026 10:53:36 +0000 (UTC) Date: Tue, 24 Mar 2026 10:53:32 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Junjie Cao Cc: qemu-devel@nongnu.org, peterx@redhat.com, farosas@suse.de Subject: Re: [PATCH v2 2/3] migration/file: fix type mismatch and NULL deref in multifd_file_recv_data Message-ID: References: <20260318140113.434-1-junjie.cao@intel.com> <20260318140113.434-3-junjie.cao@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260318140113.434-3-junjie.cao@intel.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Mar 18, 2026 at 10:01:12PM +0800, Junjie Cao wrote: > multifd_file_recv_data() stores the return value of qio_channel_pread() > (ssize_t) in a size_t variable. On I/O error the -1 return value wraps > to SIZE_MAX, producing a nonsensical read size in the error message. > > More critically, a short read (0 <= ret < data->size) is possible when > the migration file is truncated. In that case qio_channel_pread() > returns a non-negative value without setting *errp. The function then > calls error_prepend(errp, ...) which dereferences *errp -- a NULL > pointer -- crashing QEMU. > > Fix both issues by switching to qio_channel_pread_all() introduced in > the previous commit, which retries on short reads and treats > end-of-file as an error, so the caller no longer needs to check the > byte count manually. Add ERRP_GUARD() so that error_prepend() works > correctly even when errp is &error_fatal or NULL. > > Suggested-by: Peter Xu > Signed-off-by: Junjie Cao > --- > migration/file.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) Reviewed-by: Daniel P. Berrangé With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|