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 A479413B2B4; Tue, 27 Feb 2024 14:24:03 +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=1709043843; cv=none; b=WHr6GwC76nhKctIzUkVepdD9Tl8zl8oMaXVXjYJ4X24ESIyLAPI206xVyw9wPI3YuKT+fsxiSZj4EKPjg/dbd0eAEPZYGBU3LCDFRp+ieEwREL+ZW56c7qqiBmlnTD6hts1mvd6hqwGDj5bdaRooWvfP/aBUDh/qkfJ0Fu4Z3LY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709043843; c=relaxed/simple; bh=+b20WmULnicPUNZX/VpD7KAY+fS0SNISy4R0S7+StE4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bswZo3FCzuooQbXaJqrDec/QA30DmI+7Y5tQJRpwUqSxQhhKppSHXer1yp2DEjPr7ooUI48La6PagbFHR9+lAR/kyBiGtGplZOA5NjMqKQTWcD9xRdm3xTv3z9niCtx6wAySqNt3yifHBiiI5FLXoHRovH7L4gFhgpzO5SvBh6s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gYtUtI7f; 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="gYtUtI7f" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27719C433C7; Tue, 27 Feb 2024 14:24:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709043843; bh=+b20WmULnicPUNZX/VpD7KAY+fS0SNISy4R0S7+StE4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gYtUtI7f6JVqu8+q/qLzrqGG5PZ2qzmN+6ZawvqpY3+BypId6ax3sK0Zzot2AiUNf xUJtC990Ka9VBASfHrEovD8p9ut30VCpR1QnCrvutEMwhmGk1POyJ+UMBbDcNrMfPJ KEsb78mBtytwX7bYKXl11Kafzs1nd2gdx3GKP9Ec= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Howells , Tom Parkin , Simon Horman , Paolo Abeni Subject: [PATCH 5.4 57/84] l2tp: pass correct message length to ip6_append_data Date: Tue, 27 Feb 2024 14:27:24 +0100 Message-ID: <20240227131554.726924165@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131552.864701583@linuxfoundation.org> References: <20240227131552.864701583@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tom Parkin commit 359e54a93ab43d32ee1bff3c2f9f10cb9f6b6e79 upstream. l2tp_ip6_sendmsg needs to avoid accounting for the transport header twice when splicing more data into an already partially-occupied skbuff. To manage this, we check whether the skbuff contains data using skb_queue_empty when deciding how much data to append using ip6_append_data. However, the code which performed the calculation was incorrect: ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0; ...due to C operator precedence, this ends up setting ulen to transhdrlen for messages with a non-zero length, which results in corrupted packets on the wire. Add parentheses to correct the calculation in line with the original intent. Fixes: 9d4c75800f61 ("ipv4, ipv6: Fix handling of transhdrlen in __ip{,6}_append_data()") Cc: David Howells Cc: stable@vger.kernel.org Signed-off-by: Tom Parkin Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20240220122156.43131-1-tparkin@katalix.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/l2tp/l2tp_ip6.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -644,7 +644,7 @@ static int l2tp_ip6_sendmsg(struct sock back_from_confirm: lock_sock(sk); - ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0; + ulen = len + (skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0); err = ip6_append_data(sk, ip_generic_getfrag, msg, ulen, transhdrlen, &ipc6, &fl6, (struct rt6_info *)dst,