From patchwork Fri Aug 11 15:08:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabiano Rosas X-Patchwork-Id: 1820318 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=fRAAbpFj; dkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=vOVmr/n5; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RMnKL2YKgz1yf7 for ; Sat, 12 Aug 2023 01:10:14 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qUTl6-0000br-CY; Fri, 11 Aug 2023 11:09:00 -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 1qUTkz-0000Zt-BC for qemu-devel@nongnu.org; Fri, 11 Aug 2023 11:08:53 -0400 Received: from smtp-out1.suse.de ([2001:67c:2178:6::1c]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qUTkv-0006Ha-1j for qemu-devel@nongnu.org; Fri, 11 Aug 2023 11:08:51 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id E35C821887; Fri, 11 Aug 2023 15:08:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1691766525; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Sdig4Xam+KaxFnZLj6qvoskpEIm5WZWhu/1QE/MF7bM=; b=fRAAbpFjVM1AauZWTUvg+MOX/+6px2YjBz3p1rpROVJArPXAn7hPSDSvLGEYYCHSF5ZoHr dxwvn6kZxdmlRP+fXtfuTVIAgQGcZJT3Esppx1YY+pemzFonim8R0iVimw92riiPswl9pZ ejGN5fWwJDrPaOGBFXHtyufeZbOj66E= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1691766525; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Sdig4Xam+KaxFnZLj6qvoskpEIm5WZWhu/1QE/MF7bM=; b=vOVmr/n5X2isJoRzkhBUD5CTaXnIqd/s7L903QRDfKQxHFKwySyHrsJ/wOGjc00Kd1hGFi SCbobTNg7abN+eCA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 5772E13592; Fri, 11 Aug 2023 15:08:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id AG2jCPxO1mS7KwAAMHmgww (envelope-from ); Fri, 11 Aug 2023 15:08:44 +0000 From: Fabiano Rosas To: qemu-devel@nongnu.org Cc: Juan Quintela , Peter Xu , Wei Wang , Leonardo Bras Subject: [PATCH v3 03/10] migration: Fix possible race when checking to_dst_file for errors Date: Fri, 11 Aug 2023 12:08:29 -0300 Message-Id: <20230811150836.2895-4-farosas@suse.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230811150836.2895-1-farosas@suse.de> References: <20230811150836.2895-1-farosas@suse.de> MIME-Version: 1.0 Received-SPF: pass client-ip=2001:67c:2178:6::1c; envelope-from=farosas@suse.de; helo=smtp-out1.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Checking ms->to_dst_file for errors when cleaning up the return path could race with migrate_fd_cleanup() which clears the pointer. Since migrate_fd_cleanup() is reachable via qmp_migrate(), which is issued by the user, it is safer if we take the lock when reading ms->to_dst_file. Signed-off-by: Fabiano Rosas --- migration/migration.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 0067c927fa..85c171f32c 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2057,11 +2057,10 @@ static int await_return_path_close_on_source(MigrationState *ms) * need to cause it to exit. shutdown(2), if we have it, will * cause it to unblock if it's stuck waiting for the destination. */ - if (qemu_file_get_error(ms->to_dst_file)) { - WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) { - if (ms->rp_state.from_dst_file) { - qemu_file_shutdown(ms->rp_state.from_dst_file); - } + WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) { + if (ms->to_dst_file && ms->rp_state.from_dst_file && + qemu_file_get_error(ms->to_dst_file)) { + qemu_file_shutdown(ms->rp_state.from_dst_file); } }