From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1i8PQM-0002QN-3e for ath10k@lists.infradead.org; Thu, 12 Sep 2019 13:46:15 +0000 From: Kalle Valo Subject: Re: [PATCH v5 1/8] ath10k: adjust skb length in ath10k_sdio_mbox_rx_packet References: <1567679893-14029-1-git-send-email-wgong@codeaurora.org> <1567679893-14029-2-git-send-email-wgong@codeaurora.org> Date: Thu, 12 Sep 2019 16:46:09 +0300 In-Reply-To: <1567679893-14029-2-git-send-email-wgong@codeaurora.org> (Wen Gong's message of "Thu, 5 Sep 2019 18:38:06 +0800") Message-ID: <87muf9k4pq.fsf@kamboji.qca.qualcomm.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Wen Gong , Nicolas Boichat Cc: linux-wireless@vger.kernel.org, ath10k@lists.infradead.org Wen Gong writes: > From: Nicolas Boichat > > When the FW bundles multiple packets, pkt->act_len may be incorrect > as it refers to the first packet only (however, the FW will only > bundle packets that fit into the same pkt->alloc_len). > > Before this patch, the skb length would be set (incorrectly) to > pkt->act_len in ath10k_sdio_mbox_rx_packet, and then later manually > adjusted in ath10k_sdio_mbox_rx_process_packet. > > The first problem is that ath10k_sdio_mbox_rx_process_packet does not > use proper skb_put commands to adjust the length (it directly changes > skb->len), so we end up with a mismatch between skb->head + skb->tail > and skb->data + skb->len. This is quite serious, and causes corruptions > in the TCP stack, as the stack tries to coalesce packets, and relies > on skb->tail being correct (that is, skb_tail_pointer must point to > the first byte_after_ the data). > > Instead of re-adjusting the size in ath10k_sdio_mbox_rx_process_packet, > this moves the code to ath10k_sdio_mbox_rx_packet, and also add a > bounds check, as skb_put would crash the kernel if not enough space is > available. > > Tested with QCA6174 SDIO with firmware > WLAN.RMH.4.4.1-00007-QCARMSWP-1. > > Fixes: 8530b4e7b22bc3b ("ath10k: sdio: set skb len for all rx packets") > Signed-off-by: Nicolas Boichat > Signed-off-by: Wen Gong [...] > @@ -632,13 +627,29 @@ static int ath10k_sdio_mbox_rx_packet(struct ath10k *ar, > { > struct ath10k_sdio *ar_sdio = ath10k_sdio_priv(ar); > struct sk_buff *skb = pkt->skb; > + struct ath10k_htc_hdr *htc_hdr; > int ret; > > ret = ath10k_sdio_readsb(ar, ar_sdio->mbox_info.htc_addr, > skb->data, pkt->alloc_len); > + > + if (!ret) { > + /* Update actual length. The original length may be incorrect, > + * as the FW will bundle multiple packets as long as their sizes > + * fit within the same aligned length (pkt->alloc_len). > + */ > + htc_hdr = (struct ath10k_htc_hdr *)skb->data; > + pkt->act_len = le16_to_cpu(htc_hdr->len) + sizeof(*htc_hdr); > + if (pkt->act_len <= pkt->alloc_len) { > + skb_put(skb, pkt->act_len); > + } else { > + ath10k_warn(ar, "rx packet too large (%zu > %zu)\n", > + pkt->act_len, pkt->alloc_len); > + ret = -EMSGSIZE; > + } > + } > + > pkt->status = ret; > - if (!ret) > - skb_put(skb, pkt->act_len); > > return ret; > } I simplified the error handling in this function to follow the ath10k style, please check carefully that I didn't create any bugs: https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?h=pending&id=6e4d2cc5 -- https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k