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 CE70AC433FE for ; Tue, 11 Jan 2022 04:21:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347766AbiAKEVO (ORCPT ); Mon, 10 Jan 2022 23:21:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234169AbiAKEVM (ORCPT ); Mon, 10 Jan 2022 23:21:12 -0500 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4F70C06173F; Mon, 10 Jan 2022 20:21:12 -0800 (PST) Received: by mail-pl1-x641.google.com with SMTP id p14so15264601plf.3; Mon, 10 Jan 2022 20:21:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=UvMY/BpPHYLYCpXHLFkn3wGD0r030IMs3mS/Z9JjkxE=; b=B4huMDPf/I5XDFsWvuSzqemyC/KmP1kbRmHZg++C6oVqbp5JbmVAzQgwpvPHI2R75a eFndp8C17Wl5PflRaDCVZxWcEbqa5+6UBaNvURPDfheA6K3ribm3QBuU6IOQsF33gvfv CjqRwLCo8SxPYN+3PU9wnp1g8XQZT7e3InZz01HdorpXlY2u1ZmABwxOTI3afAnpZwat i9vhYGqNVJ8YqfUT5BX0bjwabLXthH/pG1n69kGxdrzJ/ttwuvaMK9HnkU1t1NJ+JTqA QeE/kZSdavrTfUBIMdC4YD/raQ0rjw+M3FbXDOLoz/5nwzR2M6KdOEqNP0tSb1lZ4ktK ruYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=UvMY/BpPHYLYCpXHLFkn3wGD0r030IMs3mS/Z9JjkxE=; b=ggOt4VYDlempqy5eehPcGASosJwhweSa72POebmjpnIyhv7hdGsTf1JHaXur0FKupa usKmbzkQp0IjUxvHx89EHw3YeQtlJ3SnjU+OAYsv2JvDI8uCrPMOt3nte61LJNfHMsKq 1u3LQ1kHsoPHhGpf7Y1B94bKMOwoE/pX3rIdCP6oiFJ9F7Kumjob+4fn8mdQOzxlmTsu 6lkER4MZfMftBMCb1UmuME7/FWAuqHmMAgVWGyMG6Mw5FidVqNDW5FXo2+2oNm79QhgN oCdQc/OewoGWL6QAdTZ5AdcCiBAW1FpkckE1jq0r9kNCrgcaTcWXw3BhIZFDILejykYY xhsA== X-Gm-Message-State: AOAM533bLX61WYnmX+brsh21D5NvtPR1hhi8fblInclWCjIGZ4ApBWvL fGbnRbLASgduwnuaHWwwnko= X-Google-Smtp-Source: ABdhPJyDr6Fn1C47Iap8ZBIHs4/z1kc6JXdQiRuNiVOxnKKraI7K5S7M44p+tPjlcF0xZ5fXCGK7BA== X-Received: by 2002:a17:902:6ac1:b0:149:7087:7b8a with SMTP id i1-20020a1709026ac100b0014970877b8amr2900110plt.174.1641874872357; Mon, 10 Jan 2022 20:21:12 -0800 (PST) Received: from slim.das-security.cn ([103.84.139.54]) by smtp.gmail.com with ESMTPSA id f7sm1062943pfe.210.2022.01.10.20.21.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Jan 2022 20:21:12 -0800 (PST) From: Hangyu Hua To: jreuter@yaina.de, ralf@linux-mips.org, davem@davemloft.net, kuba@kernel.org Cc: linux-hams@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Hangyu Hua Subject: [PATCH net] ax25: use after free in ax25_connect Date: Tue, 11 Jan 2022 12:20:48 +0800 Message-Id: <20220111042048.43532-1-hbh25y@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org sk_to_ax25(sk) needs to be called after lock_sock(sk) to avoid UAF caused by a race condition. Signed-off-by: Hangyu Hua --- net/ax25/af_ax25.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index cfca99e295b8..c5d62420a2a8 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -1127,7 +1127,7 @@ static int __must_check ax25_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags) { struct sock *sk = sock->sk; - ax25_cb *ax25 = sk_to_ax25(sk), *ax25t; + ax25_cb *ax25, *ax25t; struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)uaddr; ax25_digi *digi = NULL; int ct = 0, err = 0; @@ -1155,6 +1155,8 @@ static int __must_check ax25_connect(struct socket *sock, lock_sock(sk); + ax25 = sk_to_ax25(sk); + /* deal with restarts */ if (sock->state == SS_CONNECTING) { switch (sk->sk_state) { -- 2.25.1