From b7139960832eb56fa15d390a4b5c8c5739bd0d1a Mon Sep 17 00:00:00 2001 From: Nicolas Boichat Date: Tue, 10 Sep 2019 16:46:17 +0300 Subject: [PATCH] ath10k: adjust skb length in ath10k_sdio_mbox_rx_packet 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 Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath10k/sdio.c | 29 +++++++++++++++++++------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c index 8ed4fbd8d6c3..9870d2d095c8 100644 --- a/drivers/net/wireless/ath/ath10k/sdio.c +++ b/drivers/net/wireless/ath/ath10k/sdio.c @@ -381,16 +381,11 @@ static int ath10k_sdio_mbox_rx_process_packet(struct ath10k *ar, struct ath10k_htc_hdr *htc_hdr = (struct ath10k_htc_hdr *)skb->data; bool trailer_present = htc_hdr->flags & ATH10K_HTC_FLAG_TRAILER_PRESENT; enum ath10k_htc_ep_id eid; - u16 payload_len; u8 *trailer; int ret; - payload_len = le16_to_cpu(htc_hdr->len); - skb->len = payload_len + sizeof(struct ath10k_htc_hdr); - if (trailer_present) { - trailer = skb->data + sizeof(*htc_hdr) + - payload_len - htc_hdr->trailer_len; + trailer = skb->data + skb->len - htc_hdr->trailer_len; eid = pipe_id_to_eid(htc_hdr->eid); @@ -632,13 +627,31 @@ 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) + goto out; + + /* 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) { + ath10k_warn(ar, "rx packet too large (%zu > %zu)\n", + pkt->act_len, pkt->alloc_len); + ret = -EMSGSIZE; + goto out; + } + + skb_put(skb, pkt->act_len); + +out: pkt->status = ret; - if (!ret) - skb_put(skb, pkt->act_len); return ret; }