From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E4C2525D209; Tue, 11 Nov 2025 01:13:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762823632; cv=none; b=rd9Jeo+L9ewfqyDLvj7gF3UDONV7v/udwxEX9FoY/xfv2s8ew4lhfkJzpac/mbXzHjGLw8bUUSyC0D14+SCtBGdcN3NjAL+TWYJNfTnov7BicLgM86Yf3krCoL33+c66HlIY4y89s/hPDD8hzXjrNgwzlNtCK1RxqQvUXI/O0rw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762823632; c=relaxed/simple; bh=TboICJPvuCnUHM8FDxaBtaaWxC25mmV/jduLscEoawo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sYEjE33X/hRB+DQKDHWQWkUlqmCAAXWyz+BtnuvwXIJNsHCaWEWPcVVyNf7gPEHBhVRgg9xc3wYuvxXu3JUrb7Lr39+YC3g/0zNoFNeQrlhqNJhWN7neN/Ptj6FkbTHLekOBHpYBrk7Nr/l0B1LyrZIPhmkMC13BByXeLafz7ZA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gn8wvORC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gn8wvORC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5088EC2BC86; Tue, 11 Nov 2025 01:13:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1762823631; bh=TboICJPvuCnUHM8FDxaBtaaWxC25mmV/jduLscEoawo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gn8wvORCrnvHSN5sJd5xdZlYXCEZ/fn3IzsVdVFs4ZaFepJaEoheZyQv+Oq/wyf9G D0aS4YuvbuJ7LuM0AgNpWCLqkHEGrnkgtbsm/y2EGPyznR23j7iVCQdfKzGg4dRoNu deXW+8qv9nfhPso5DdR/FLTgbOjsz4VGAxs7RYfE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 276/565] tcp: use dst_dev_rcu() in tcp_fastopen_active_disable_ofo_check() Date: Tue, 11 Nov 2025 09:42:12 +0900 Message-ID: <20251111004533.092397371@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251111004526.816196597@linuxfoundation.org> References: <20251111004526.816196597@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit b62a59c18b692f892dcb8109c1c2e653b2abc95c ] Use RCU to avoid a pair of atomic operations and a potential UAF on dst_dev()->flags. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20250828195823.3958522-8-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp_fastopen.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 86c995dc1c5e5..f9460e7531ba7 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -575,11 +575,12 @@ void tcp_fastopen_active_disable_ofo_check(struct sock *sk) } } else if (tp->syn_fastopen_ch && atomic_read(&sock_net(sk)->ipv4.tfo_active_disable_times)) { - dst = sk_dst_get(sk); - dev = dst ? dst_dev(dst) : NULL; + rcu_read_lock(); + dst = __sk_dst_get(sk); + dev = dst ? dst_dev_rcu(dst) : NULL; if (!(dev && (dev->flags & IFF_LOOPBACK))) atomic_set(&sock_net(sk)->ipv4.tfo_active_disable_times, 0); - dst_release(dst); + rcu_read_unlock(); } } -- 2.51.0