package/kernel/mac80211/patches/319-v4.12-0011-brcmfmac-Make-skb-header-writable-before-use.patch

   1 From 9cc4b7cb86cbcc6330a3faa8cd65268cd2d3c227 Mon Sep 17 00:00:00 2001
   2 From: James Hughes <james.hughes@raspberrypi.org>
   3 Date: Tue, 25 Apr 2017 10:15:06 +0100
   4 Subject: [PATCH] brcmfmac: Make skb header writable before use
   5
   6 The driver was making changes to the skb_header without
   7 ensuring it was writable (i.e. uncloned).
   8 This patch also removes some boiler plate header size
   9 checking/adjustment code as that is also handled by the
  10 skb_cow_header function used to make header writable.
  11
  12 Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
  13 Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
  14 Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
  15 ---
  16  .../net/wireless/broadcom/brcm80211/brcmfmac/core.c   | 19 +++++--------------
  17  1 file changed, 5 insertions(+), 14 deletions(-)
  18
  19 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
  20 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
  21 @@ -211,22 +211,13 @@ static netdev_tx_t brcmf_netdev_start_xm
  22                 goto done;
  23         }
  24
  25 -       /* Make sure there's enough room for any header */
  26 -       if (skb_headroom(skb) < drvr->hdrlen) {
  27 -               struct sk_buff *skb2;
  28 -
  29 -               brcmf_dbg(INFO, "%s: insufficient headroom\n",
  30 +       /* Make sure there's enough writable headroom*/
  31 +       ret = skb_cow_head(skb, drvr->hdrlen);
  32 +       if (ret < 0) {
  33 +               brcmf_err("%s: skb_cow_head failed\n",
  34                           brcmf_ifname(ifp));
  35 -               drvr->bus_if->tx_realloc++;
  36 -               skb2 = skb_realloc_headroom(skb, drvr->hdrlen);
  37                 dev_kfree_skb(skb);
  38 -               skb = skb2;
  39 -               if (skb == NULL) {
  40 -                       brcmf_err("%s: skb_realloc_headroom failed\n",
  41 -                                 brcmf_ifname(ifp));
  42 -                       ret = -ENOMEM;
  43 -                       goto done;
  44 -               }
  45 +               goto done;
  46         }
  47
  48         /* validate length for ether packet */