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 lists1p.gnu.org (lists1p.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 E5030F34C49 for ; Mon, 13 Apr 2026 13:46:50 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wCHcY-00057K-B6; Mon, 13 Apr 2026 09:46:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wCHcX-00056l-1g for qemu-devel@nongnu.org; Mon, 13 Apr 2026 09:46:33 -0400 Received: from mgamail.intel.com ([198.175.65.14]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wCHcV-0002H1-GE for qemu-devel@nongnu.org; Mon, 13 Apr 2026 09:46:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776087992; x=1807623992; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=jRIYr/DJPikQoTUtLLf24NEzeIOFia6aU6GKa/BmoKA=; b=JuPavCBXydKLribUPiYNn7ONXxn6tvNffsOv1MzoYyZdX+uIPCFWBHq6 a7QcWHekemdFdKBsBUtnkQbYtMvVAtw4yXW/UuLU+DlzBv7ahdBi3AMev cVgxd2Gm3+uLfAUHIjREqucHL2keofRuiS0V/DMBliHrZeMIBqjGC/gaI UvED3JHS5YWSjrOwmXRiqM7TgElYr6s0XhIcKVIA+IWps4SiVPN/XcF8o FsGEjAgw3eDyqgx/ZMHNzG0KhnPR/ZBaZVnI1KKXv7O+Dcl77g52TNsFD fWjV2vhHjwMrNWfNJKEV0RLZq9Zvtyneeq198rc8uMh8LDIMCqjiZ9sIu Q==; X-CSE-ConnectionGUID: HFgKHtr+TIC+F5/5Z6eEiA== X-CSE-MsgGUID: 8M0HvRKgSwqlJyA52+tIxw== X-IronPort-AV: E=McAfee;i="6800,10657,11758"; a="80885675" X-IronPort-AV: E=Sophos;i="6.23,177,1770624000"; d="scan'208";a="80885675" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2026 06:46:30 -0700 X-CSE-ConnectionGUID: mRaTV8cTR++7NbeU2U3tEA== X-CSE-MsgGUID: ffP93G3MQ9SAB2yOrdMGKw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,177,1770624000"; d="scan'208";a="234770429" Received: from junjie-optiplex-micro-plus-7010.bj.intel.com ([10.238.152.98]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2026 06:46:29 -0700 From: Junjie Cao To: qemu-devel@nongnu.org Cc: berrange@redhat.com, peterx@redhat.com, farosas@suse.de, junjie.cao@intel.com Subject: [PATCH v3 3/4] migration/file: fix type mismatch and NULL deref in multifd_file_recv_data Date: Tue, 14 Apr 2026 05:45:48 +0800 Message-ID: <20260413214549.926435-4-junjie.cao@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260413214549.926435-1-junjie.cao@intel.com> References: <20260413214549.926435-1-junjie.cao@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=198.175.65.14; envelope-from=junjie.cao@intel.com; helo=mgamail.intel.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DATE_IN_FUTURE_06_12=1.947, DKIMWL_WL_HIGH=-0.54, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org 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 a previous patch, 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. Fixes: a49d15a38d3d ("migration/multifd: Support incoming mapped-ram stream format") Suggested-by: Peter Xu Reviewed-by: Daniel P. Berrangé Signed-off-by: Junjie Cao --- migration/file.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/migration/file.c b/migration/file.c index 5618aced49..0853188601 100644 --- a/migration/file.c +++ b/migration/file.c @@ -254,15 +254,16 @@ int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov, int multifd_file_recv_data(MultiFDRecvParams *p, Error **errp) { + ERRP_GUARD(); MultiFDRecvData *data = p->data; - size_t ret; + int ret; - ret = qio_channel_pread(p->c, (char *) data->opaque, - data->size, data->file_offset, errp); - if (ret != data->size) { + ret = qio_channel_pread_all(p->c, (char *) data->opaque, + data->size, data->file_offset, errp); + if (ret != 0) { error_prepend(errp, - "multifd recv (%u): read 0x%zx, expected 0x%zx", - p->id, ret, data->size); + "multifd recv (%u): ", + p->id); return -1; } -- 2.43.0