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 6454DC678D4 for ; Tue, 7 Mar 2023 17:27:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231625AbjCGR1s (ORCPT ); Tue, 7 Mar 2023 12:27:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231435AbjCGR1N (ORCPT ); Tue, 7 Mar 2023 12:27:13 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2461996605 for ; Tue, 7 Mar 2023 09:22:27 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id D1991B818F6 for ; Tue, 7 Mar 2023 17:22:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0640EC433EF; Tue, 7 Mar 2023 17:22:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678209744; bh=qhn9Mz5Xf0sM/28BzNMo9OYqjwBhnKFBO9plANfz3mY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AG8k5niuaAVQhNUXXvmcpD94UeC+D40NMK8iK1tAy+EHOmMODs/jfzATrAW1tjGF6 l9Cuw7NPB4BgpZiTOB3XHavizAc0oS/QsbZD6usIxYbSdtc/P2cCuT9psAssUSBgd6 l7ACDPLitjip79BFINfdV+RA8564mZuJC3+iM8bs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "D. Wythe" , Larysa Zaremba , Wenjia Zhang , "David S. Miller" , Sasha Levin Subject: [PATCH 6.2 0317/1001] net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link() Date: Tue, 7 Mar 2023 17:51:29 +0100 Message-Id: <20230307170035.308375114@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: D. Wythe [ Upstream commit e40b801b3603a8f90b46acbacdea3505c27f01c0 ] There is a certain chance to trigger the following panic: PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48" #0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7 #1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a #2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60 #3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7 #4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715 #5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654 #6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62 [exception RIP: ib_alloc_mr+19] RIP: ffffffffc0c9cce3 RSP: ffff9456c1cc7c38 RFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000004 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88c1ea281d00 R8: 000000020a34ffff R9: ffff88c1350bbb20 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000010 R14: ffff88c1ab040a50 R15: ffff88c1ea281d00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc] #8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc] #9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc] The reason here is that when the server tries to create a second link, smc_llc_srv_add_link() has no protection and may add a new link to link group. This breaks the security environment protected by llc_conf_mutex. Fixes: 2d2209f20189 ("net/smc: first part of add link processing as SMC server") Signed-off-by: D. Wythe Reviewed-by: Larysa Zaremba Reviewed-by: Wenjia Zhang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/af_smc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index e12d4fa5aece6..d9413d43b1045 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1826,8 +1826,10 @@ static int smcr_serv_conf_first_link(struct smc_sock *smc) smc_llc_link_active(link); smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE); + mutex_lock(&link->lgr->llc_conf_mutex); /* initial contact - try to establish second link */ smc_llc_srv_add_link(link, NULL); + mutex_unlock(&link->lgr->llc_conf_mutex); return 0; } -- 2.39.2