From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A8978347506; Tue, 11 Aug 2026 12:28:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786451333; cv=none; b=ehrTgj9rgyLJg7hDjFbDsfLVPsHCBtjQ+VurMQ646ap9XoVkUf3HNfTwQlZSbdw7LPxpg8yYGZeunzSZDC43ZpDoixwbkzGGw6jXKR8HrtBSAAUwUZQXQsRbjqL8HI5XN4rSZqTmnfDVUPQu490SFu8TKHOhnjylHvAQW8eMOoY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786451333; c=relaxed/simple; bh=1HJM2k2JV3t2FQTApIRUtJS3EfIQx0T4Q8RZFnZ1pCY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cavm1vE85VEOQevj0kmynhgsHdjJvqItJc6o1Dr5vwYEzXHkbetUsQ8B0B8JrtR/FfHfYVH2ntey7q+qGuBzUyyr7qDkvFt5nvG2iSqSEJ5B/PRScrBlJ5t9fcrWG3Wn0SKKDCeTrNDdtLkC98UxLK+31WKjjsKssvlcBhBvYog= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Nvnqsi03; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Nvnqsi03" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 753801F000E9; Tue, 11 Aug 2026 12:28:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786451332; bh=UdIsiKVFhDlUuCmo+fjPrnJmZm9dNzKypop6Jsqk+DY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Nvnqsi03F+RfEqUTxbHVk4abr18YXEWVCCrDXlLBMcqDVcVUMHQKjBe+rTy10zjrR nvGI8iMn94HEUCE2YgUDchFhUss04at+jYO36ynOfDrqY9Geab3qSitraUVxIJTL3o HoMkM5l1aDheIiTj3GbUX6kY024CeyPuo9ZQaxT5XKBFalTXyBM4hGceXIbkk5zzrQ ttiZLVixvpiHINlPVQdV/gL1K0LP2E6zY6WQzbfzgLfaDOv3pPWXLkn/lir0BDo0PQ jnwJwoa0tPjGWYEC5oHXzkNDLQZUHmOHxk2BorFkxci5zk0+kNXAwNhwnPAtElzePU JTipzctWNekHQ== Date: Tue, 11 Aug 2026 13:28:48 +0100 From: Simon Horman To: raoxu Cc: andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, kees@kernel.org, linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: usb: lg-vl600: fix Ethernet header on fragmented RX packets Message-ID: <20260811122848.GE51943@horms.kernel.org> References: <30CC616506DE5BC4+20260810084435.2099229-1-raoxu@uniontech.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <30CC616506DE5BC4+20260810084435.2099229-1-raoxu@uniontech.com> On Mon, Aug 10, 2026 at 04:44:35PM +0800, raoxu wrote: > From: Xu Rao > > The LG VL600 RX path can assemble one device frame from multiple USB RX > URBs. In the single-URB case, the input skb passed by usbnet is also the > buffer being parsed, so @skb and @buf point to the same skb. > > When a frame is completed from current_rx_buf, however, @buf points to > the assembled skb while @skb still points to the last URB fragment. > vl600_rx_fixup() returns @buf to the network stack in that path, but it > currently obtains the Ethernet header from @skb. > > As a result, the source/destination address fixups and the IPv6 ethertype > fixup can be applied to the final fragment instead of the assembled skb > that is actually delivered. Use @buf for the Ethernet header so the > fixups are applied to the packet being parsed and returned. > > This has likely gone unnoticed because the common single-URB path has > @skb == @buf and therefore behaves correctly. > > Fixes: 7a635ea98999 ("net/usb: Ethernet quirks for the LG-VL600 4G modem") > Signed-off-by: Xu Rao Reviewed-by: Simon Horman