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authorDaniel Stone <daniels@collabora.com>2017-07-26 12:24:10 +0100
committerKalle Valo <kvalo@codeaurora.org>2017-07-27 14:02:16 +0300
commit58f36b4526add4870476e1dc97a8467cf16aeee6 (patch)
treed95ab3fd79451caa17ec36932d99e6dbf5d5e648
parentd755cbc26e8295ae8e5d30425364e093b4247a85 (diff)
downloadlinux-58f36b4526add4870476e1dc97a8467cf16aeee6.tar.bz2
brcmfmac: Don't grow SKB by negative size
The commit to rework the headroom check in start_xmit() now calls pxskb_expand_head() unconditionally if the header is CoW. Unfortunately, it does so with the delta between the extant headroom and the header length, which may be negative if there is already sufficient headroom. pskb_expand_head() does allow for size being 0, in which case it just copies, so clamp the header delta to zero. Opening Chrome (and all my tabs) on a PCIE device was enough to reliably hit this. Fixes: 270a6c1f65fe ("brcmfmac: rework headroom check in .start_xmit()") Signed-off-by: Daniel Stone <daniels@collabora.com> Cc: Arend Van Spriel <arend.vanspriel@broadcom.com> Cc: James Hughes <james.hughes@raspberrypi.org> Cc: Hante Meuleman <hante.meuleman@broadcom.com> Cc: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com> Cc: Franky Lin <franky.lin@broadcom.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
-rw-r--r--drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
index 2153e8062b4c..5cc3a07dda9e 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
@@ -214,7 +214,7 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
/* Make sure there's enough writeable headroom */
if (skb_headroom(skb) < drvr->hdrlen || skb_header_cloned(skb)) {
- head_delta = drvr->hdrlen - skb_headroom(skb);
+ head_delta = max_t(int, drvr->hdrlen - skb_headroom(skb), 0);
brcmf_dbg(INFO, "%s: insufficient headroom (%d)\n",
brcmf_ifname(ifp), head_delta);