From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CDDE31FECA for ; Tue, 16 Sep 2025 21:48:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758059298; cv=none; b=dkvcRm8RrMFXw1z8Un0nmTAvN7gGYYNjgElfgGcCaJvwxC1+CcctlLAWH9o3plG7D2LisjU8j+rNhVog8uvLyq8fWjIQHMjOUnYQuoKO3yIVOqbSdEN6PyFCMS5JISuuGUNzbUMEjQBHJS4V+uaME7V+MTU6VmiuGvfkLhGZdyw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758059298; c=relaxed/simple; bh=YSSulxDP6s1Wrz4iDsg9JsJkoY2Nm053uEUy1N4tYtg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=KnmgZfD/85NoJR8XOoQaXECSGoLSMDwmtGcISR2G7G1kNBqlT+34Fz3rcEZIN3Vtcksh8Q1ObXX2ObxWh1vz3K5eM1bSdWoq/9fjEg+KeSiclUAZYGP4Gf4ZUl+lc5O0a4/aOuPI8r/Cl/b2f5Gk8xDqrD+IeyN+f/qJCCLigO8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=iqNxm9Kb; arc=none smtp.client-ip=209.85.215.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="iqNxm9Kb" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-b4e796ad413so7579649a12.2 for ; Tue, 16 Sep 2025 14:48:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1758059293; x=1758664093; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=QYA3HnzQOBu6R3F9r2KwX8kmxhTDpMCfN49huqtLQ6Q=; b=iqNxm9Kbeug5G+sC+2ST5ZpDXpfBMsabDg90ZUGnW6sA4BIiMkQLvRoNzd3ukkT27a vvyaHjANDZT6CsJSZEMsFJIvX644SF1oGLFa46cIO6iXOTi+Buk79mPxG0wGWf7UBa54 7Nb2ERPDam5fwbOi0iYSafQyiT2lN6DFBMt2RvRP6sNm24FtTn//rNfGKeBBOZrNKrVt DwePnGh0/7OS8c/We0swV2gerPrzan5fm5R/aAmT6YCfzoA9q1VfHXiU1iTKwJJ4JRBf 3Upwex5PBCysgjdGJTcHh4hfaAc3dp37kwZTfQCDODzm3DaNs2cYOXDJMIM67CbEcnme 99iA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758059293; x=1758664093; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=QYA3HnzQOBu6R3F9r2KwX8kmxhTDpMCfN49huqtLQ6Q=; b=qzldlFpvXfV1rZZeM47/Zx7oooq0HJCOQuGmJVqG3nITKO9gJOmx4TeZBqgIkgIyYq QRKTzD9H3j8WpL1EtqmkYbxlJ2t/riUJ8p9B8v+MG+4k+//8NJVROyGtQ8w1oBfa6c82 A9NFJsPwpcxTAgNywZJatrLBIiGKDJ5iGgYdCpRFQOisD7gCPwfJWW4cIZOr8zqx08DO lhQ4tI90kaGLBL6VtbiZxUS81hZbPBb1z+l4oHsFABcbtX/DTAl4hgjSnQmW1YU5KHJd ENY7Tk4xCzPQcOAxZ+W2yel8RT9aEPtc0RiVw1WaaqaH+PSb4PH9Xey+yIoF2YFcVunU Zhow== X-Forwarded-Encrypted: i=1; AJvYcCX/YRM69FCBKSsKCJM+A2FSKY1BFtOn0xulgsJcd88YtHkI6Tmksqkb68A2d/WpfZxj35GzyXI=@vger.kernel.org X-Gm-Message-State: AOJu0YwMMqUaH6rXijYC/HbaigcHgEUr4iiVCVeF6v86cHKlqdf//N5S 61RuxXriafFn4snlIYvG7shC5w/m2UFyJzrpTv0W+66p/ZaDy1oOHULV2R2xbcy3lXXbhMusy37 wqOKsLQ== X-Google-Smtp-Source: AGHT+IGCiZRhStZbsGgcBUZOeZjjNRqlhkYFi3NqH85Hc/hM8KYu2P/kGQ1wV5UKozmiFv1pHaBoJ8aCzb0= X-Received: from pgq3.prod.google.com ([2002:a63:1043:0:b0:b52:3192:18e1]) (user=kuniyu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:1584:b0:245:5765:dd5b with SMTP id adf61e73a8af0-2602ac8422fmr23954327637.25.1758059293325; Tue, 16 Sep 2025 14:48:13 -0700 (PDT) Date: Tue, 16 Sep 2025 21:47:25 +0000 In-Reply-To: <20250916214758.650211-1-kuniyu@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250916214758.650211-1-kuniyu@google.com> X-Mailer: git-send-email 2.51.0.384.g4c02a37b29-goog Message-ID: <20250916214758.650211-8-kuniyu@google.com> Subject: [PATCH v2 net-next 7/7] mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable(). From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Kuniyuki Iwashima , Kuniyuki Iwashima , netdev@vger.kernel.org, Matthieu Baerts , Mat Martineau , Geliang Tang Content-Type: text/plain; charset="UTF-8" mptcp_active_enable() is called from subflow_finish_connect(), which is icsk->icsk_af_ops->sk_rx_dst_set() and it's not always under RCU. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dst_dev_rcu(). Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole") Signed-off-by: Kuniyuki Iwashima --- Cc: Matthieu Baerts Cc: Mat Martineau Cc: Geliang Tang --- net/mptcp/ctrl.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c index c0e516872b4b..e8ffa62ec183 100644 --- a/net/mptcp/ctrl.c +++ b/net/mptcp/ctrl.c @@ -501,12 +501,15 @@ void mptcp_active_enable(struct sock *sk) struct mptcp_pernet *pernet = mptcp_get_pernet(sock_net(sk)); if (atomic_read(&pernet->active_disable_times)) { - struct dst_entry *dst = sk_dst_get(sk); + struct net_device *dev; + struct dst_entry *dst; - if (dst && dst->dev && (dst->dev->flags & IFF_LOOPBACK)) + rcu_read_lock(); + dst = __sk_dst_get(sk); + dev = dst ? dst_dev_rcu(dst) : NULL; + if (dev && (dev->flags & IFF_LOOPBACK)) atomic_set(&pernet->active_disable_times, 0); - - dst_release(dst); + rcu_read_unlock(); } } -- 2.51.0.384.g4c02a37b29-goog