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 041E4EB64DD for ; Thu, 15 Jun 2023 11:44:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344600AbjFOLog (ORCPT ); Thu, 15 Jun 2023 07:44:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344287AbjFOLnu (ORCPT ); Thu, 15 Jun 2023 07:43:50 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8D243A8D; Thu, 15 Jun 2023 04:40:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B99E963A3C; Thu, 15 Jun 2023 11:40:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CF29C433C8; Thu, 15 Jun 2023 11:40:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686829219; bh=C+7t1mrgPlpYYMk5TwLT8REVaqGEg0d/uW1IlD46v2c=; h=From:To:Cc:Subject:Date:From; b=rEDlnckkJb4/6Qat3TuQRsGr+WUUrWw0YB+kasbw9GFQ41Wdxu3nbQZil1KGCxN9e ujeUN/UKVCVlhgnvIWR5e0bcYM1+n6qs5V1+SgW5N6kaf3X9GnkFUynvsL4FnAuKyC jhHBlufaLk3eUpP3rJcv0p3066BJAbCr3Dor1FW2b0K7j0+4ceS0G6XlqgnNhU1Yg9 Jf6KMNqtv5Cj/QzdSBkXzZfhST31R0jHHrpGQsgN+fu6W8IkrfrN/iWFDA54qeYhcq Cs4dNxFg1K9c42xjlTStkTHCxuo++SnXb5puFANrh9Gl+/7Sr8cXfTFIfYUp3fA9dk 7oJiLUN3qIapQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Maurizio Lombardi , Mike Christie , "Martin K . Petersen" , Sasha Levin , d.bogdanov@yadro.com, peilin.ye@bytedance.com, yang.lee@linux.alibaba.com, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 1/6] scsi: target: iscsi: Prevent login threads from racing between each other Date: Thu, 15 Jun 2023 07:40:09 -0400 Message-Id: <20230615114016.649846-1-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.14.318 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Maurizio Lombardi [ Upstream commit 2a737d3b8c792400118d6cf94958f559de9c5e59 ] The tpg->np_login_sem is a semaphore that is used to serialize the login process when multiple login threads run concurrently against the same target portal group. The iscsi_target_locate_portal() function finds the tpg, calls iscsit_access_np() against the np_login_sem semaphore and saves the tpg pointer in conn->tpg; If iscsi_target_locate_portal() fails, the caller will check for the conn->tpg pointer and, if it's not NULL, then it will assume that iscsi_target_locate_portal() called iscsit_access_np() on the semaphore. Make sure that conn->tpg gets initialized only if iscsit_access_np() was successful, otherwise iscsit_deaccess_np() may end up being called against a semaphore we never took, allowing more than one thread to access the same tpg. Signed-off-by: Maurizio Lombardi Link: https://lore.kernel.org/r/20230508162219.1731964-4-mlombard@redhat.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/iscsi/iscsi_target_nego.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c index 07335357418c8..d94f711afee07 100644 --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -1067,6 +1067,7 @@ int iscsi_target_locate_portal( iscsi_target_set_sock_callbacks(conn); login->np = np; + conn->tpg = NULL; login_req = (struct iscsi_login_req *) login->req; payload_length = ntoh24(login_req->dlength); @@ -1136,7 +1137,6 @@ int iscsi_target_locate_portal( */ sessiontype = strncmp(s_buf, DISCOVERY, 9); if (!sessiontype) { - conn->tpg = iscsit_global->discovery_tpg; if (!login->leading_connection) goto get_target; @@ -1153,9 +1153,11 @@ int iscsi_target_locate_portal( * Serialize access across the discovery struct iscsi_portal_group to * process login attempt. */ + conn->tpg = iscsit_global->discovery_tpg; if (iscsit_access_np(np, conn->tpg) < 0) { iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR, ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE); + conn->tpg = NULL; ret = -1; goto out; } -- 2.39.2