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 93D07C433F5 for ; Thu, 17 Mar 2022 22:10:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229655AbiCQWL3 (ORCPT ); Thu, 17 Mar 2022 18:11:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbiCQWL2 (ORCPT ); Thu, 17 Mar 2022 18:11:28 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91C4C1FDFE3; Thu, 17 Mar 2022 15:10:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647555010; x=1679091010; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=QpWbczOzLS4au3qRyyNQY/DJiO8OZbjCj8/kWLrheTM=; b=WnehGXa1UhX8180TRwCdm1/0jqguxcSXcsdS4S/wqGEsYNdCkRiQD6it 3avw0I6IaHwhJQEkXpckJ55X+XPDdBaNktEsinN8XZqLmE4AMAM5m2OnP rV+Y6GleoDLAAg1ptNy/pBZ6fm+iOu9ao/ZDhwBVQFKOrF9dmgijxKand cZUL3dYgDu0QSZRMCofKs6WhhbPKBrtAfrLJTuQ7p6UX+73olle+O7tKd xx5Nbqj/Xz6ljkCxLdqmhpKHh8OlbgWbP4BloGT+4jxINML4ActMjoE7r ayTZwjpiHqSyDEv8H40oaW9DCesA03qMvU08ywTJL681jxR73G7mCKil9 A==; X-IronPort-AV: E=McAfee;i="6200,9189,10289"; a="255821066" X-IronPort-AV: E=Sophos;i="5.90,190,1643702400"; d="scan'208";a="255821066" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2022 15:10:10 -0700 X-IronPort-AV: E=Sophos;i="5.90,190,1643702400"; d="scan'208";a="599259580" Received: from mjmartin-desk2.amr.corp.intel.com (HELO mjmartin-desk2.intel.com) ([10.251.9.212]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2022 15:10:09 -0700 From: Mat Martineau To: netdev@vger.kernel.org Cc: Yonglong Li , davem@davemloft.net, kuba@kernel.org, matthieu.baerts@tessares.net, mptcp@lists.linux.dev, stable@vger.kernel.org, Paolo Abeni , Mat Martineau Subject: [PATCH net] mptcp: Fix crash due to tcp_tsorted_anchor was initialized before release skb Date: Thu, 17 Mar 2022 15:09:53 -0700 Message-Id: <20220317220953.426024-1-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yonglong Li Got crash when doing pressure test of mptcp: =========================================================================== dst_release: dst:ffffa06ce6e5c058 refcnt:-1 kernel tried to execute NX-protected page - exploit attempt? (uid: 0) BUG: unable to handle kernel paging request at ffffa06ce6e5c058 PGD 190a01067 P4D 190a01067 PUD 43fffb067 PMD 22e403063 PTE 8000000226e5c063 Oops: 0011 [#1] SMP PTI CPU: 7 PID: 7823 Comm: kworker/7:0 Kdump: loaded Tainted: G E Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.2.1 04/01/2014 Call Trace: ? skb_release_head_state+0x68/0x100 ? skb_release_all+0xe/0x30 ? kfree_skb+0x32/0xa0 ? mptcp_sendmsg_frag+0x57e/0x750 ? __mptcp_retrans+0x21b/0x3c0 ? __switch_to_asm+0x35/0x70 ? mptcp_worker+0x25e/0x320 ? process_one_work+0x1a7/0x360 ? worker_thread+0x30/0x390 ? create_worker+0x1a0/0x1a0 ? kthread+0x112/0x130 ? kthread_flush_work_fn+0x10/0x10 ? ret_from_fork+0x35/0x40 =========================================================================== In __mptcp_alloc_tx_skb skb was allocated and skb->tcp_tsorted_anchor will be initialized, in under memory pressure situation sk_wmem_schedule will return false and then kfree_skb. In this case skb->_skb_refdst is not null because_skb_refdst and tcp_tsorted_anchor are stored in the same mem, and kfree_skb will try to release dst and cause crash. Fixes: f70cad1085d1 ("mptcp: stop relying on tcp_tx_skb_cache") Cc: stable@vger.kernel.org Reviewed-by: Paolo Abeni Signed-off-by: Yonglong Li Signed-off-by: Mat Martineau --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 1c72f25f083e..014c9d88f947 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1196,6 +1196,7 @@ static struct sk_buff *__mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, g tcp_skb_entail(ssk, skb); return skb; } + tcp_skb_tsorted_anchor_cleanup(skb); kfree_skb(skb); return NULL; } base-commit: 551acdc3c3d2b6bc97f11e31dcf960bc36343bfc -- 2.35.1