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 0EBBF13F006; Tue, 27 Feb 2024 13:54:53 +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=1709042094; cv=none; b=aYlXneLFxxINFsMpj4QiyQJKjX4K7R38dHWpPH+sprnAbUMdCD/9X52Yuz11VEXLR/KPw5eAF6KpJDZHWsRcUIc9TGJ7NPsSWI7LliXjGvwXKYHdDenGpRGWVy02DSC0ewnau6ifzfztw0be5wjkMz4nmH7OPcs/jZTZzNk+KYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709042094; c=relaxed/simple; bh=YXMuWM+dYJgKH/x2iSx5mdmWMx3jqrXVHnqpw8alejk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ldjgRVr+MUHvYNPgW+IzihVXZQmRvZY/zORWKhN3PsiA5NzmWBRifZzOKkAz/NAjEUJJIBrAcWEEhpKhjwh1baonN4mktQPICFVf7GXRsLqURGvtfsrxi4UFJEk/Je4d2n2PvafOhi1+AwtG3kWErdQeeeJ6hkjtc9rIZSuX2Is= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nk7vTPv9; 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="nk7vTPv9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B5FEC433F1; Tue, 27 Feb 2024 13:54:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709042093; bh=YXMuWM+dYJgKH/x2iSx5mdmWMx3jqrXVHnqpw8alejk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nk7vTPv9eqT4vTs3Xdr0rTFczGE2KvKbnFkL/emxReBsoq9FeJtwXo4zrMcAh1RSC gVvfEnTskJvxxobleVPMC0ktyumQbwrRSz9LDuaVHCutUKYvJFxeh+vWBRBF/pB9It y3JdK/hoGa9GaoLNeVximZZVQgmknhIcaZ2W9pvc= 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 6.6 176/299] l2tp: pass correct message length to ip6_append_data Date: Tue, 27 Feb 2024 14:24:47 +0100 Message-ID: <20240227131631.508246819@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131625.847743063@linuxfoundation.org> References: <20240227131625.847743063@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 6.6-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 @@ -627,7 +627,7 @@ 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,