Commit c0469da2 authored Sep 10, 2019 by Nicolas Boichat Committed by Greg Kroah-Hartman Jan 27, 2020

ath10k: adjust skb length in ath10k_sdio_mbox_rx_packet



[ Upstream commit b7139960832eb56fa15d390a4b5c8c5739bd0d1a ]

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: 8530b4e7 ("ath10k: sdio: set skb len for all rx packets")
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 5207c6d7

drivers/net/wireless/ath/ath10k/sdio.c

+21 −8

Original line number	Diff line number	Diff line
		@@ -392,16 +392,11 @@ 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);

		@@ -638,14 +633,32 @@ 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);
		pkt->status = ret;
		if (!ret)
		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;

		return ret;
		}